pax_global_header00006660000000000000000000000064132207742330014515gustar00rootroot0000000000000052 comment=71ea6974bf0a5b58a3cfb1fd6c9f4aa00ee57e84 graph-20180131-git/000077500000000000000000000000001322077423300136405ustar00rootroot00000000000000graph-20180131-git/.gitignore000066400000000000000000000000651322077423300156310ustar00rootroot00000000000000*.fasl *.lx32fsl *.lx64fsl stuff scratch.lisp ltxpng graph-20180131-git/COPYING000066400000000000000000001045131322077423300146770ustar00rootroot00000000000000 GNU GENERAL PUBLIC LICENSE Version 3, 29 June 2007 Copyright (C) 2007 Free Software Foundation, Inc. Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. Preamble The GNU General Public License is a free, copyleft license for software and other kinds of works. The licenses for most software and other practical works are designed to take away your freedom to share and change the works. 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Copyright (C) This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . Also add information on how to contact you by electronic and paper mail. If the program does terminal interaction, make it output a short notice like this when it starts in an interactive mode: Copyright (C) This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. This is free software, and you are welcome to redistribute it under certain conditions; type `show c' for details. 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But first, please read . graph-20180131-git/NOTES000066400000000000000000000026201322077423300144530ustar00rootroot00000000000000Notes and Tasks -*- org -*- * Notes ** simpler backend data structure What if we only used 1 hash to hold all nodes and edges..., and what if nodes could hold other nodes in their edge list, and edges could hold other edges in their node list, what sort of structure would this be? A useful generalization of a graph? * Tasks [4/9] ** DONE min cut Some notes in the stuff/ directory. ** TODO breadth/depth first maps ** DONE minimum spanning tree Prim's algorithm ** TODO minimum edge coloring ** DONE clustering coefficient the clustering coefficient \begin{equation*} C = \frac{\text{number of closed connected triples}}{\text{number of connected triples}} \end{equation*} ** TODO measure assortativity http://en.wikipedia.org/wiki/Assortativity Should take an optional :key function which defaults to node degree. ** DONE random graph generators [2/2] http://en.wikipedia.org/wiki/Random_graph Both of the following types of random graphs - [X] [[http://en.wikipedia.org/wiki/Edgar_Gilbert][Edgar_Gilbert]] - [X] [[http://en.wikipedia.org/wiki/Erd%C5%91s%E2%80%93R%C3%A9nyi_model][Erdos-Renyi]] ** TODO more attractive documentation like it or not, people will initially look for pictures - graph-dot -> images in documentation - graph-json -> images in documentation ** TODO graph Laplacian http://web.mit.edu/newsoffice/2013/short-algorithm-long-range-consequences-0301.html graph-20180131-git/README000066400000000000000000000011231322077423300145150ustar00rootroot00000000000000GRAPH - simple graph data structure and algorithms The GRAPH library strives for simplicity both in backing data structures and in usage. Graphs and Digraphs are represented as CLOS objects with methods and algorithms provided for graph manipulation and analysis. Note: currently this library is only supported on SBCL and Clozure CL because of the need to create hashes with custom equality tests, however custom equality tests are commonly supported so extending to other lisps should be simple. Patches welcome. For more information see http://eschulte.github.com/graph. graph-20180131-git/dot.lisp000066400000000000000000000225661322077423300153320ustar00rootroot00000000000000;;; graph-dot.lisp --- serialize graphs to and from DOT format ;; Copyright (C) Eric Schulte and Thomas Dye 2013 ;; Licensed under the Gnu Public License Version 3 or later ;;; Commentary ;; Functions for reading/writing graphs from/to the ;; [graphviz](http://www.graphviz.org/) DOT format. ;; ;; Many graphviz properties and exposed as keyword arguments to the ;; `to-dot` function. ;; ;; (defvar *graph* (populate (make-instance 'digraph) ;; :nodes '(a b c d e f) ;; :edges-w-values '(((a b) . 3) ;; ((b c) . 2) ;; ((c d) . 1) ;; ((d b) . 2) ;; ((b e) . 3)))) ;; ;; (let ((ccs (mapcar #'cons (connected-components *graph*) ;; '(1 2 3 4)))) ;; (to-dot-file *graph* "dot-graph-1.dot" ;; :node-attrs ;; (list (cons :fillcolor ;; (lambda (n) (cdr (assoc-if {member n} ccs)))) ;; (cons :style ;; (constantly "filled")) ;; (cons :colorscheme ;; (constantly "set34"))))) ;; ;; ;; ;; Or less colorfully. ;; ;; (setf *graph* (populate (make-instance 'digraph) ;; :edges '((A T2) (T1 B) (T2 B) (T2 C) (T1 D)))) ;; ;; (let ((s1 (make-subgraph :attributes '(("color" . "lightgrey") ;; ("label" . "One" )) ;; :node-list (first ;; (connected-components ;; *graph* ;; :type :unilateral)))) ;; (s2 (make-subgraph :attributes '(("color" . "lightgrey") ;; ("label" . "Two" )) ;; :node-list (second ;; (connected-components ;; *graph* ;; :type :unilateral))))) ;; (to-dot-file *graph* "dot-graph-2.dot" ;; :subgraphs (list s1 s2))) ;; ;; ;;; Code: (defpackage #:graph/dot (:use :common-lisp :alexandria :metabang-bind :named-readtables :curry-compose-reader-macros :graph :cl-ppcre) (:export :to-dot :to-dot-file :from-dot :make-subgraph)) (in-package :graph/dot) (in-readtable :curry-compose-reader-macros) ;;; Visualization (defstruct rank "The information needed to specify a DOT rank statement. VALUE expects a string and NODE-LIST expects a list." value node-list) (defun rank-print (r) "Returns a string containing a DOT rank statement. R is a RANK structure." (when (rank-p r)) (with-output-to-string (out) (when (and (rank-value r) (rank-node-list r)) (format out "{rank=~a;" (rank-value r)) (mapc (lambda (n) (format out " ~s;" n)) (rank-node-list r)) (format out " }~%")))) (defstruct subgraph "The information needed to specify a DOT subgraph. NODE-ATTRIBUTES, EDGE-ATTRIBUTES, and ATTRIBUTES expect assoc lists, and NODE-LIST expects a list." node-attributes edge-attributes attributes ranks node-list) (defun subgraph-print (s) "Returns a string containing a DOT subgraph statement. S is a SUBGRAPH structure." (when (subgraph-p s) (with-output-to-string (out) (format out "subgraph ~a {~%" (string (gensym "cluster_"))) (when (subgraph-node-attributes s) (format out " node [~a];~%" (mapc (lambda (pair) (format out "~a=~a, " (car pair) (cdr pair))) (subgraph-node-attributes s)))) (when (subgraph-edge-attributes s) (format out " edge [~a];~%" (mapc (lambda (pair) (format out "~a=~a, " (car pair) (cdr pair))) (subgraph-edge-attributes s)))) (when (subgraph-attributes s) (mapc (lambda (pair) (format out " ~a=\"~a\";~%" (car pair) (cdr pair))) (subgraph-attributes s))) (when (subgraph-ranks s) (mapcar #'rank-print (subgraph-ranks s))) (when (subgraph-node-list s) (mapc (lambda (n) (format out " ~a;~%" n)) (subgraph-node-list s))) (format out " }~%")))) (defun edge-to-dot (edge type attrs &optional stream) (format stream " \"~a\" ~a \"~a\" ~{~a~^ ~};~%" (first edge) (ecase type (graph "--") (digraph "->")) (second edge) (mapcar (lambda-bind ((attr . fn)) (let ((val (funcall fn edge))) (if val (if (search "URL" (string attr)) (format nil "[~a=~a]" (string-downcase (string attr) :end (- (length (string attr)) 3)) val) (format nil "[~(~a~)=~a]" attr val)) ""))) attrs))) (defun node-to-dot (node attrs &optional stream) (format stream " \"~a\" ~{~a~^ ~};~%" node (mapcar (lambda-bind ((attr . fn)) (let ((val (funcall fn node))) (if val (if (search "URL" (string attr)) (format nil "[~a=~a]" attr val) (format nil "[~(~a~)=~a]" attr val)) ""))) attrs))) (defgeneric to-dot (graph &key stream attributes node-attrs edge-attrs subgraphs ranks) (:documentation "Print the dot code representing GRAPH. The keyword argument ATTRIBUTES takes an assoc list with DOT graph attribute (name . value) pairs. NODE-ATTRS and EDGE-ATTRS also take assoc lists of DOT graph attributes and functions taking nodes or edges respectively and returning values. The DOT graph, node, and edge attributes are described at http://www.graphviz.org/doc/info/attrs.html. SUBGRAPHS is a list of SUBGRAPH structures. RANKS is a list of RANK structures.")) (defmethod to-dot ((graph graph) &key (stream t) attributes node-attrs edge-attrs subgraphs ranks) ;; by default edges are labeled with their values (unless (assoc :label edge-attrs) (push (cons :label {edge-value graph}) edge-attrs)) (format stream "~a to_dot {~%~{~a~}}~%" (intern (string-downcase (type-of graph))) (append (mapcar (lambda-bind ((a . b)) (if (search "URL" (string a)) (format nil " ~a=~a;~%" a b) (format nil " ~(~a~)=~a;~%" a b))) attributes) (mapcar {node-to-dot _ node-attrs} (nodes graph)) (mapcar {edge-to-dot _ (type-of graph) edge-attrs} (edges graph)) (mapcar #'subgraph-print subgraphs) (mapcar #'rank-print ranks)))) (defgeneric to-dot-file (graph path &key attributes node-attrs edge-attrs subgraphs ranks) (:documentation "Write a dot representation of GRAPH to PATH.")) (defmethod to-dot-file ((graph graph) path &key attributes node-attrs edge-attrs subgraphs ranks) (with-open-file (out path :direction :output :if-exists :supersede) (to-dot graph :stream out :attributes attributes :node-attrs node-attrs :edge-attrs edge-attrs :subgraphs subgraphs :ranks ranks))) (defun from-dot (dot-string) "Parse the DOT format string DOT-STRING into a graph. More robust behavior may be achieved through parsing the output of the dot executable." (flet ((string->symbol (string) (intern (string-upcase string)))) (let* ((graph-type-re "^ *((di)?graph)") (spec-re "[\\s]*(\\[([^]]+)\\])?;") (node-name-re "[\\s]*\"?([a-zA-Z0-9_]+)\"?") (node-spec-re (concatenate 'string node-name-re spec-re)) (edge-spec-re (concatenate 'string node-name-re "[\\s]+([->]+)" node-name-re spec-re)) (label-name-re "label=(\"([^\"]+)\"|([^, ]+))[,\\]]") (number-re "[0-9.\/e]+") (graph (multiple-value-bind (string matches) (scan-to-strings graph-type-re dot-string) (declare (ignorable string)) (make-instance (string->symbol (aref matches 0)))))) ;; add nodes (do-register-groups (node spec) (node-spec-re dot-string) (declare (ignorable spec)) (unless (member node '("node" "graph") :test 'string=) (add-node graph (string->symbol node)))) ;; add edges (do-register-groups (left arrow right spec) (edge-spec-re dot-string) (declare (ignorable arrow)) (multiple-value-bind (matchp regs) (scan-to-strings label-name-re spec) (add-edge graph (mapcar #'string->symbol (list left right)) (when matchp (if (scan number-re (aref regs 1)) (read-from-string (aref regs 1)) (aref regs 1)))))) graph))) graph-20180131-git/graph.asd000066400000000000000000000007451322077423300154400ustar00rootroot00000000000000(defsystem :graph :description "simple library for building and manipulating graphs" :version "0.0.0" :author ("Eric Schulte " "Thomas Dye") :licence "GPL V3" :class :package-inferred-system :defsystem-depends-on (:asdf-package-system) :depends-on (alexandria metabang-bind named-readtables curry-compose-reader-macros graph/graph)) (register-system-packages "femlisp" '(:fl.function)) graph-20180131-git/graph.lisp000066400000000000000000001444261322077423300156450ustar00rootroot00000000000000;;; graph.lisp --- because its easier to write than to learn such a library ;; Copyright (C) Eric Schulte and Thomas Dye 2012-2013 ;; Licensed under the Gnu Public License Version 3 or later ;;; Commentary ;; Graphs are composed of two hash tables, nodes and edges. The node ;; hash is keyed by node and holds the edges containing that node, ;; while the edge hash is keyed by edge containing any optional edge ;; value. ;; ;; Nodes Edges ;; ------- ------- ;; +----Graph G-----+ key | value key | value ;; | 3 2 | -----+--------- -------+---------- ;; | a---b---c g | a | (a b) (a b) | 3 ;; | 1| |1 | b | (b d) (b c) (b d) | 1 ;; | d---e---f | c | (b c) (c e) (b c) | 2 ;; | 2 3 | d | (b d) (d e) (c e) | 1 ;; +----------------+ e | (d e) (c e) (d e) | 2 ;; f | (e f) (e f) | 3 ;; g | ;; ;; Graphs are CLOS objects which are constructed with the usual `make ;; instance` and are populated with the `populate` function. ;; ;; (defvar *graph* (populate (make-instance 'graph) ;; :nodes '(a b c d e f g) ;; :edges-w-values '(((a b) . 3) ;; ((b d) . 1) ;; ((b c) . 2) ;; ((c e) . 1) ;; ((d e) . 2) ;; ((e f) . 3)))) ;; ;; Standard accessors are provided. ;; ;; * (nodes *graph*) ;; (A B C D E F G) ;; ;; * (edges *graph*) ;; ((A B) (B D) (B C) (C E) (D E) (E F)) ;; ;; * (node-edges *graph* 'b) ;; ((B C) (B D) (A B)) ;; ;; * (edge-value *graph* '(d e)) ;; 2 ;; ;; Nodes and edges may be removed using `delete-node` and ;; `delete-edge`, or using setf methods on any of the accessors above. ;; ;; * (delete-edge *graph* '(e f)) ;; 3 ;; ;; * (edges *graph*) ;; ((A B) (B D) (B C) (C E) (D E)) ;; ;; * (setf (nodes *graph*) (remove 'a (nodes *graph*))) ;; (B C D E F G) ;; ;; * (edges *graph*) ;; ((B D) (B C) (C E) (D E)) ;; ;; Some more sophisticated graph algorithms are implemented. A couple ;; are shown below, see the dictionary for a complete list. ;; ;; * (shortest-path *graph* 'b 'e) ;; ((B C) (C E)) ;; ;; * (connected-components *graph*) ;; ((G) (B D C E) (F)) ;; ;; * (setf (nodes *graph*) '(B D C E)) ;; (B C D E) ;; ;; * (min-cut *graph*) ;; ((B C) (E D)) ;; 2 ;; ;; Additionally digraphs represent graphs with directed edges. ;; Starting with the original graph above we get the following. ;; ;; * (strongly-connected-components *graph*) ;; ((G) (D F E C B A)) ;; ;; * (strongly-connected-components (digraph-of *graph*)) ;; ((G) (A) (B) (D) (C) (E) (F)) ;; ;; * (delete-edge *graph* '(d e)) ;; 2 ;; ;; * (push '(e d) (edges *graph*)) ;; ((A B) (B D) (B C) (C E) (E D) (E F)) ;; ;; * (push '(d c) (edges *graph*)) ;; ((A B) (B D) (B C) (C E) (E D) (E F) (D C)) ;; ;; * (strongly-connected-components (digraph-of *graph*)) ;; ((G) (A) (B) (D E C) (F)) ;;; Code: (uiop/package:define-package :graph/graph (:nicknames :graph) (:use :common-lisp :alexandria :metabang-bind :named-readtables :curry-compose-reader-macros) (:export :graph :digraph :copy :digraph-of :graph-of :populate :graph-equal ;; Serialization :to-plist :from-plist :to-adjacency-matrix :to-value-matrix :from-value-matrix ;; Simple Graph Methods :edges :edges-w-values :nodes :nodes-w-values :has-node-p :has-edge-p :subgraph :add-node :add-edge :node-edges :degree :indegree :outdegree :delete-node :edge-value :delete-edge :reverse-edges ;; Complex Graph Methods :merge-nodes :merge-edges :edge-neighbors :neighbors :precedents :connected-component :connectedp :connected-components :topological-sort :levels ;; Cycles and strongly connected components :strongly-connected-components :basic-cycles :cycles :minimum-spanning-tree :connected-groups-of-size :closedp :clustering-coefficient :cliques ;; Shortest Path :shortest-path ;; Max Flow :residual :add-paths :max-flow ;; Min Cut :min-cut ;; Random Graph generation :preferential-attachment-populate :erdos-renyi-populate :erdos-renyi-graph :erdos-renyi-digraph :edgar-gilbert-populate :edgar-gilbert-graph :edgar-gilbert-digraph ;; Centrality :farness :closeness :betweenness :katz-centrality ;; Degeneracy :degeneracy :k-cores)) (in-package :graph) (in-readtable :curry-compose-reader-macros) ;;; Special hashes keyed for edges (defun edge-equalp (edge1 edge2) (set-equal edge1 edge2)) (defun sxhash-edge (edge) (sxhash (sort (copy-tree edge) (if (numberp (car edge)) #'< #'string<)))) #+sbcl (sb-ext:define-hash-table-test edge-equalp sxhash-edge) #+clisp (ext:define-hash-table-test edge-equalp edge-equalp sxhash-edge) (defun dir-edge-equalp (edge1 edge2) (tree-equal edge1 edge2)) #+sbcl (sb-ext:define-hash-table-test dir-edge-equalp sxhash) #+clisp (ext:define-hash-table-test dir-edge-equalp dir-edge-equalp sxhash) (defun make-edge-hash-table () #+sbcl (make-hash-table :test 'edge-equalp) #+clisp (make-hash-table :test 'edge-equalp) #+ccl (make-hash-table :test 'edge-equalp :hash-function 'sxhash-edge) #-(or sbcl clisp ccl) (error "unsupport lisp distribution")) (defun make-diedge-hash-table () #+sbcl (make-hash-table :test 'dir-edge-equalp) #+clisp (make-hash-table :test 'dir-edge-equalp) #+ccl (make-hash-table :test 'dir-edge-equalp :hash-function 'sxhash) #-(or sbcl clisp ccl) (error "unsupport lisp distribution")) ;;; Graph objects and basic methods (defclass graph () ((node-h :initarg :node-h :accessor node-h :initform (make-hash-table)) (edge-h :initarg :edge-h :accessor edge-h :initform (make-edge-hash-table)) (edge-eq :initarg :edge-eq :accessor edge-eq :initform 'edge-equalp)) (:documentation "A graph consisting of `nodes' connected by `edges'. Nodes must be numbers symbols or keywords. Edges may be assigned arbitrary values, although some functions assume numeric values (e.g., `merge-nodes', `merge-edges', `max-flow' and `min-cut').")) (defclass digraph (graph) ((edge-h :initarg :edge-h :accessor edge-h :initform (make-diedge-hash-table)) (edge-eq :initarg :edge-eq :accessor edge-eq :initform 'dir-edge-equalp)) (:documentation "A `graph' with directed edges.")) (defun copy-hash (hash &optional test comb) "Return a copy of HASH. Optional argument TEST specifies a new equality test to use for the copy. Second optional argument COMB specifies a function to use to combine the values of elements of HASH which collide in the copy due to a new equality test specified with TEST." (let ((copy #+sbcl (make-hash-table :test (or test (hash-table-test hash))) #+clisp (make-hash-table :test (or test (hash-table-test hash))) #+ccl (make-hash-table :test (or test (hash-table-test hash)) :hash-function (case (or test (hash-table-test hash)) (edge-equalp 'sxhash-edge) ((dir-edge-equalp equalp) 'sxhash))) #-(or sbcl clisp ccl) (error "unsupported lisp distribution"))) (maphash (lambda (k v) (setf (gethash k copy) (if (and (gethash k copy) comb) (funcall comb (gethash k copy) v) v))) hash) copy)) (defun node-hash-equal (hash1 hash2) "Test node hashes HASH1 and HASH2 for equality." (set-equal (hash-table-alist hash1) (hash-table-alist hash2) :test (lambda (a b) (and (equalp (car a) (car b)) (set-equal (cdr a) (cdr b) :test 'tree-equal))))) (defun edge-hash-equal (hash1 hash2) "Test edge hashes HASH1 and HASH2 for equality." (set-equal (hash-table-alist hash1) (hash-table-alist hash2) :test 'equalp)) (defgeneric copy (graph) (:documentation "Return a copy of GRAPH.")) (defmethod copy ((graph graph)) (make-instance (type-of graph) :node-h (copy-hash (node-h graph)) :edge-h (copy-hash (edge-h graph)) :edge-eq (edge-eq graph))) (defgeneric digraph-of (graph) (:documentation "Copy GRAPH into a `digraph' and return.")) (defmethod digraph-of ((graph graph)) (make-instance 'digraph :node-h (copy-hash (node-h graph)) :edge-h (copy-hash (edge-h graph)) :edge-eq (edge-eq graph))) (defgeneric graph-of (digraph) (:documentation "Copy DIGRAPH into a `graph' and return.")) (defmethod graph-of ((digraph digraph)) (make-instance 'graph :node-h (copy-hash (node-h digraph)) :edge-h (copy-hash (edge-h digraph) 'equalp) :edge-eq (edge-eq digraph))) (defgeneric populate (graph &key nodes edges edges-w-values) (:documentation "Populate the nodes and edges of GRAPH based on keyword arguments.")) (defmethod populate ((graph graph) &key nodes edges edges-w-values) (mapc {add-node graph} nodes) (mapc {add-edge graph} edges) (setf (edges-w-values graph) edges-w-values) graph) (defgeneric graph-equal (graph1 graph2) (:documentation "Compare GRAPH1 and GRAPH2 for equality.")) (defmethod graph-equal ((graph1 graph) (graph2 graph)) (every (lambda-bind ((test key)) ;; TODO: digraph's need a stricter graph-equal (apply test (append (mapcar key (list graph1 graph2))))) '((eq type-of) (equal edge-eq) (edge-hash-equal edge-h) (node-hash-equal node-h)))) ;;; Serialize graphs (defgeneric to-plist (graph &key node-fn edge-fn) (:documentation "Serialize GRAPH as a plist. Keyword arguments NODE-FN and EDGE-FN will be called on a node or edge and should return a plist of data to associate with the given node or edge in the results.")) (defmethod to-plist ((graph graph) &key node-fn edge-fn) (let ((counts (make-hash-table)) (counter -1)) (list :nodes (mapcar (lambda (node) (append (list :name node) (when node-fn (funcall node-fn node)))) (mapc (lambda (n) (setf (gethash n counts) (incf counter))) (nodes graph))) :edges (map 'list (lambda (edge value) (append (list :edge edge :value value) (when edge-fn (funcall edge-fn edge)))) (mapcar {mapcar {gethash _ counts}} (edges graph)) (mapcar {edge-value graph} (edges graph)))))) (defgeneric from-plist (graph plist) (:documentation "Populate GRAPH with the contents of PLIST.")) (defmethod from-plist ((graph graph) plist) (let ((nodes (map 'vector {getf _ :name} (getf plist :nodes)))) (populate graph :nodes (coerce nodes 'list) :edges-w-values (mapcar (lambda (el) (cons (mapcar {aref nodes} (getf el :edge)) (getf el :value))) (getf plist :edges))))) (defgeneric to-value-matrix (graph) (:documentation "Return the value matrix of GRAPH.")) (defmethod to-value-matrix ((graph graph)) (let ((node-index-hash (make-hash-table)) (counter -1)) (mapc (lambda (node) (setf (gethash node node-index-hash) (incf counter))) (nodes graph)) (let ((matrix (make-array (list (1+ counter) (1+ counter)) :initial-element nil))) (mapc (lambda-bind (((a b) . value)) (setf (aref matrix (gethash a node-index-hash) (gethash b node-index-hash)) (or value t))) (edges-w-values graph)) matrix))) (defgeneric from-value-matrix (graph matrix) (:documentation "Populate GRAPH from the value matrix MATRIX.")) (defmethod from-value-matrix ((graph graph) matrix) (bind (((as bs) (array-dimensions matrix))) (assert (= as bs) (matrix) "Value matrix ~S must be square." matrix) (loop :for a :below as :do (loop :for b :below bs :do (when (aref matrix a b) (add-edge graph (list a b) (if (eq t (aref matrix a b)) nil (aref matrix a b))))))) graph) ;;; Simple graph methods (defgeneric edges (graph) (:documentation "Return a list of the edges in GRAPH.")) (defmethod edges ((graph graph)) (loop :for key :being :each :hash-key :of (edge-h graph) :collect key)) (defgeneric (setf edges) (new graph) (:documentation "Set the edges in GRAPH to NEW.")) (defmethod (setf edges) (new (graph graph)) (mapc {delete-edge graph} (set-difference (edges graph) new :test (edge-eq graph))) (mapc {add-edge graph} (set-difference new (edges graph) :test (edge-eq graph))) (edges graph)) (defgeneric edges-w-values (graph) (:documentation "Return an alist of edges of GRAPH with their values.")) (defmethod edges-w-values ((graph graph) &aux alist) (maphash (lambda (edge value) (push (cons edge value) alist)) (edge-h graph)) alist) (defgeneric (setf edges-w-values) (new graph) (:documentation "Set the edges of graph to edges and values in NEW.")) (defmethod (setf edges-w-values) (new (graph graph)) (mapc (lambda-bind ((edge . value)) (add-edge graph edge value)) new)) (defgeneric nodes (graph) (:documentation "Return a list of the nodes in GRAPH.")) (defmethod nodes ((graph graph)) (loop :for key :being :each :hash-key :of (node-h graph) :collect key)) (defgeneric (setf nodes) (new graph) (:documentation "Set the nodes in GRAPH to NEW.")) (defmethod (setf nodes) (new (graph graph)) (mapc {delete-node graph} (set-difference (nodes graph) new)) (mapc {add-node graph} (set-difference new (nodes graph))) (nodes graph)) (defgeneric nodes-w-values (graph) (:documentation "Return an alist of nodes of GRAPH with their values.")) (defmethod nodes-w-values ((graph graph) &aux alist) (maphash (lambda (node value) (push (cons node value) alist)) (node-h graph)) alist) (defgeneric has-node-p (graph node) (:documentation "Return `true' if GRAPH has node NODE.")) (defmethod has-node-p ((graph graph) node) (multiple-value-bind (value included) (gethash node (node-h graph)) (declare (ignorable value)) included)) (defgeneric has-edge-p (graph edge) (:documentation "Return `true' if GRAPH has edge EDGE.")) (defmethod has-edge-p ((graph graph) edge) (multiple-value-bind (value included) (gethash edge (edge-h graph)) (declare (ignorable value)) included)) (defgeneric subgraph (graph nodes) (:documentation "Return the subgraph of GRAPH restricted to NODES.")) (defmethod subgraph ((graph graph) nodes) (let ((g (copy graph))) (setf (nodes g) nodes) g)) (defgeneric add-node (graph node) (:documentation "Add NODE to GRAPH.")) (defmethod add-node ((graph graph) node) ;; NOTE: This limitation on the types of node simplifies the ;; equality tests, and the use of nodes as hash keys ;; throughout the remainder of this library. In fact the ;; addition of type-annotations around node quality operations ;; may improve performance. The desire for more complex node ;; structures, may often be met by maintaining a hash table ;; outside of the graph which maps graph nodes to the more ;; complex object related to the node. (assert (or (numberp node) (symbolp node)) (node) "Nodes must be numbers, symbols or keywords, not ~S.~%Invalid node:~S" (type-of node) node) (unless (has-node-p graph node) (setf (gethash node (node-h graph)) nil) node)) (defgeneric add-edge (graph edge &optional value) (:documentation "Add EDGE to GRAPH with optional VALUE. The nodes of EDGE are also added to GRAPH.")) (defmethod add-edge ((graph graph) edge &optional value) (mapc (lambda (node) (add-node graph node) (pushnew (case (type-of graph) (graph (remove-duplicates edge)) (digraph edge)) (gethash node (node-h graph)) :test (edge-eq graph))) edge) (setf (gethash edge (edge-h graph)) value) edge) (defgeneric node-edges (graph node) (:documentation "Return the value of NODE in GRAPH.")) (defmethod node-edges ((graph graph) node) (multiple-value-bind (edges included) (gethash node (node-h graph)) (assert included (node graph) "~S doesn't include ~S" graph node) (copy-tree edges))) (defgeneric degree (graph node) (:documentation "Return the degree of NODE in GRAPH.")) (defmethod degree ((graph graph) node) (length (node-edges graph node))) (defgeneric indegree (digraph node) (:documentation "The number of edges directed to NODE in GRAPH.")) (defmethod indegree ((digraph digraph) node) (length (remove-if-not [{member node} #'cdr] (node-edges digraph node)))) (defgeneric outdegree (digraph node) (:documentation "The number of edges directed from NODE in DIGRAPH.")) (defmethod outdegree ((digraph digraph) node) (length (remove-if-not [{equal node} #'car] (node-edges digraph node)))) (defgeneric transmitterp (digraph node) (:documentation "Returns t if node is a transmitter, i.e., has indegree of 0 and positive outdegree.")) (defmethod transmitterp ((digraph digraph) node) (and (eq (indegree digraph node) 0) (> (outdegree digraph node) 0))) (defgeneric receiverp (digraph node) (:documentation "Returns t if node is a receiver, i.e., has outdegree of 0 and positive indegree.")) (defmethod receiverp ((digraph digraph) node) (and (eq (outdegree digraph node) 0) (> (indegree digraph node) 0))) (defgeneric isolatep (digraph node) (:documentation "Returns t if node is an isolate, i.e., both indegree and outdegree are 0.")) (defmethod isolatep ((digraph digraph) node) (and (eq (indegree digraph node) 0) (eq (outdegree digraph node) 0))) (defgeneric carrierp (digraph node) (:documentation "Returns t if node is a carrier, i.e., both indegree and outdegree are 1.")) (defmethod carrierp ((digraph digraph) node) (and (eq (indegree digraph node) 1) (eq (outdegree digraph node) 1))) (defgeneric ordinaryp (digraph node) (:documentation "Returns t if node is ordinary, i.e., is not a transmitter, receiver, isolate, or carrier.")) (defmethod ordinaryp ((digraph digraph) node) (not (or (transmitterp digraph node) (receiverp digraph node) (isolatep digraph node) (carrierp digraph node)))) (defgeneric transmitters (digraph) (:documentation "Return a list of the transmitters in digraph.")) (defmethod transmitters ((digraph digraph)) (let ((r)) (dolist (n (nodes digraph) r) (when (transmitterp digraph n) (push n r))))) (defgeneric receivers (digraph) (:documentation "Return a list of the receivers in digraph.")) (defmethod receivers ((digraph digraph)) (let ((r)) (dolist (n (nodes digraph) r) (when (receiverp digraph n) (push n r))))) (defgeneric isolates (digraph) (:documentation "Return a list of the isolated node in digraph.")) (defmethod isolates ((digraph digraph)) (let ((r)) (dolist (n (nodes digraph) r) (when (isolatep digraph n) (push n r))))) (defgeneric ordinaries (digraph) (:documentation "Return a list of the ordinary nodes in digraph.")) (defmethod ordinaries ((digraph digraph)) (let ((r)) (dolist (n (nodes digraph) r) (when (ordinaryp digraph n) (push n r))))) (defgeneric (setf node-edges) (new graph node) ;; TODO: seg-faults in clisp (:documentation "Set the edges of NODE in GRAPH to NEW. Delete and return the old edges of NODE in GRAPH.")) (defmethod (setf node-edges) (new (graph graph) node) (prog1 (mapc {delete-edge graph} (gethash node (node-h graph))) (mapc {add-edge graph} new))) (defgeneric delete-node (graph node) (:documentation "Delete NODE from GRAPH. Delete and return the old edges of NODE in GRAPH.")) (defmethod delete-node ((graph graph) node) (prog1 (mapcar (lambda (edge) (cons edge (delete-edge graph edge))) (node-edges graph node)) (remhash node (node-h graph)))) (defgeneric edge-value (graph edge) (:documentation "Return the value of EDGE in GRAPH.")) (defmethod edge-value ((graph graph) edge) (multiple-value-bind (value included) (gethash edge (edge-h graph)) (assert included (edge graph) "~S doesn't include ~S" graph edge) value)) (defgeneric (setf edge-value) (new graph edge) (:documentation "Set the value of EDGE in GRAPH to NEW.")) (defmethod (setf edge-value) (new (graph graph) edge) (setf (gethash edge (edge-h graph)) new)) (defgeneric delete-edge (graph edge) (:documentation "Delete EDGE from GRAPH. Return the old value of EDGE.")) (defmethod delete-edge ((graph graph) edge) (prog1 (edge-value graph edge) (mapc (lambda (node) (setf (gethash node (node-h graph)) (remove edge (gethash node (node-h graph)) :test (edge-eq graph)))) edge) (remhash edge (edge-h graph)))) (defgeneric reverse-edges (graph) (:documentation "Return a copy of GRAPH with all edges reversed.")) (defmethod reverse-edges ((graph graph)) (populate (make-instance (type-of graph)) :nodes (nodes graph) :edges-w-values (mapcar (lambda-bind ((edge . value)) (cons (reverse edge) value)) (edges-w-values graph)))) ;;; Complex graph methods (defgeneric merge-nodes (graph node1 node2 &key new) (:documentation "Combine NODE1 and NODE2 in GRAPH into the node NEW. All edges of NODE1 and NODE2 in GRAPH will be combined into a new node of value NEW. Edges between only NODE1 and NODE2 will be removed.")) (defmethod merge-nodes ((graph graph) node1 node2 &key (new node1)) ;; replace all removed edges with NEW instead of NODE1 or NODE2 (mapcar (lambda-bind ((edge . value)) (let ((e (mapcar (lambda (n) (if (member n (list node1 node2)) new n)) edge))) (if (has-edge-p graph e) (when (and (edge-value graph e) value) (setf (edge-value graph e) (+ (edge-value graph e) value))) (add-edge graph e value)))) ;; drop edges between only node1 and node2 (remove-if-not [{set-difference _ (list node1 node2)} #'car] ;; delete both nodes keeping their edges and values (prog1 (append (delete-node graph node1) (delete-node graph node2)) ;; add the new node (add-node graph new)))) graph) (defgeneric merge-edges (graph edge1 edge2 &key value) (:documentation "Combine EDGE1 and EDGE2 in GRAPH into a new EDGE. Optionally provide a value for the new edge, the values of EDGE1 and EDGE2 will be combined.")) (defmethod merge-edges ((graph graph) edge1 edge2 &key value) (add-edge graph (remove-duplicates (append edge1 edge2)) (or value (when (and (edge-value graph edge1) (edge-value graph edge2)) (+ (edge-value graph edge1) (edge-value graph edge2))))) (append (delete-edge graph edge1) (delete-edge graph edge2))) (defgeneric edge-neighbors (graph edge) (:documentation "Return all edges which share a node with EDGE in GRAPH.")) (defmethod edge-neighbors ((graph graph) edge) (mapcan {node-edges graph} edge)) (defgeneric neighbors (graph node) (:documentation "Return all nodes which share an edge with NODE in GRAPH.")) (defmethod neighbors ((graph graph) node) (apply {concatenate 'list} (node-edges graph node))) (defmethod neighbors ((digraph digraph) node) (mapcan [#'cdr {member node}] (node-edges digraph node))) (defgeneric precedents (digraph node) (:documentation "Return all nodes preceding NODE in an edge of DIGRAPH.")) (defmethod precedents ((digraph digraph) node) (mapcan [#'cdr {member node} #'reverse] (node-edges digraph node))) (defgeneric connected-component (graph node &key type) (:documentation "Return the connected component of NODE in GRAPH. The TYPE keyword argument only has an effect for directed graphs in which it may be set to one of the following with :STRONG being the default value. :STRONG ..... connections only traverse edges along the direction of the edge :WEAK ....... connections may traverse edges in any direction regardless of the edge direction :UNILATERAL . two nodes a and b connected iff a is strongly connected to b or b is strongly connected to a")) (defun connected-component- (node neighbor-fn) ;; Helper function for `connected-component'. (let ((from (list node)) (seen (list node))) (loop :until (null from) :do (let ((next (remove-duplicates (mapcan neighbor-fn from)))) (setf from (set-difference next seen)) (setf seen (union next seen)))) (reverse seen))) (defmethod connected-component ((graph graph) node &key type) (declare (ignorable type)) (connected-component- node {neighbors graph})) (defmethod connected-component ((digraph digraph) node &key type) (ecase (or type :strong) (:strong (connected-component- node {neighbors digraph})) (:weak (connected-component- node {neighbors (graph-of digraph)})) (:unilateral (let ((weakly (connected-component- node {neighbors (graph-of digraph)})) (strongly (connected-component- node {neighbors digraph}))) ;; keep weakly connected components which are strongly ;; connected to NODE in digraph or to which NODE is strongly ;; connected in the directional compliment of digraph (union strongly (remove-if-not [{member node} {connected-component (reverse-edges digraph)}] (set-difference weakly strongly))))))) (defgeneric connectedp (graph &key type) (:documentation "Return true if the graph is connected. TYPE keyword argument is passed to `connected-components'.")) (defmethod connectedp ((graph graph) &key type) (declare (ignorable type)) (let ((nodes (nodes graph))) (subsetp (nodes graph) (connected-component graph (car nodes))))) (defmethod connectedp ((digraph digraph) &key type) (every [{subsetp (nodes digraph)} (lambda (n) (connected-component digraph n :type type))] (nodes digraph))) (defgeneric connected-components (graph &key type) (:documentation "Return a list of the connected components of GRAPH. Keyword TYPE is passed to `connected-component' and only has effect for directed graphs. Returns strongly connected components of a directed graph by default.")) (defmethod connected-components ((graph graph) &key type) (flet ((cc-helper () (let ((nodes (sort (nodes graph) #'< :key {degree graph})) ccs) (loop :until (null nodes) :do (let ((cc (connected-component graph (car nodes) :type type))) (setf nodes (set-difference nodes cc)) (push cc ccs))) ccs))) (cond ((and type (eq (type-of graph) 'graph)) (warn "type parameter has no effect for undirected graphs") (cc-helper)) ((eq type :unilateral) (warn "unilateral connected component partition may not be well defined") (cc-helper)) ((or (eq type :strong) (and (null type) (eq (type-of graph) 'digraph))) (strongly-connected-components graph)) (t (cc-helper))))) (defgeneric topological-sort (digraph) (:documentation "Returns a topologically ordered list of the nodes in DIGRAPH, such that, for each edge in DIGRAPH, the start of the edge appears in the list before the end of the edge.")) (defmethod topological-sort (digraph) (assert (null (basic-cycles digraph)) (digraph) "~S has a cycle so no topological sort is possible" digraph) (let ((index (make-hash-table)) stack) (labels ((visit (node) (mapc (lambda (neighbor) (unless (gethash neighbor index) (visit neighbor))) (neighbors digraph node)) ;; mark this node (setf (gethash node index) 1) (push node stack))) (mapc (lambda (node) (unless (gethash node index) (visit node))) (nodes digraph))) stack)) (defgeneric levels (digraph &key alist) (:documentation "Assign a positive integer to each node in DIGRAPH, called its level, where, for each directed edge (a b) the corresponding integers satisfy a < b. Returns either a hash table where the nodes are keys and the levels are values, or an association list of nodes and their levels, along with the number of levels in DIGRAPH.")) (defmethod levels (digraph &key alist) (let ((longest (make-hash-table))) (dolist (x (topological-sort digraph)) (let ((max-val 0) (incoming (precedents digraph x))) (if incoming (progn (dolist (y incoming) (when (> (gethash y longest) max-val) (setf max-val (gethash y longest)))) (setf (gethash x longest) (+ 1 max-val))) (setf (gethash x longest) max-val)))) (values (if alist (nreverse (hash-table-alist longest)) longest) (+ 1 (reduce #'max (hash-table-values longest)))))) ;;; Cycles and strongly connected components (defgeneric strongly-connected-components (graph) (:documentation "Return the nodes of GRAPH partitioned into strongly connected components. Uses Tarjan's algorithm.")) (defmethod strongly-connected-components ((graph graph)) (let ((index (make-hash-table)) (lowlink (make-hash-table)) (counter 0) stack sccs) (labels ((tarjan (node) ;; mark this node (setf (gethash node index) counter) (setf (gethash node lowlink) counter) (incf counter) (push node stack) ;; consider successors (mapc (lambda (neighbor) (cond ((not (gethash neighbor index)) (tarjan neighbor) (setf (gethash node lowlink) (min (gethash node lowlink) (gethash neighbor lowlink)))) ((member neighbor stack) (setf (gethash node lowlink) (min (gethash node lowlink) (gethash neighbor index)))))) (neighbors graph node)) ;; is NODE the root of a strongly connected component (when (= (gethash node index) (gethash node lowlink)) (push (loop :for v = (pop stack) :collect v :until (eq v node)) sccs)))) (mapc (lambda (node) (unless (gethash node index) (tarjan node))) (nodes graph))) sccs)) (defgeneric basic-cycles (graph) (:documentation "Return all basic cycles in the GRAPH.")) (defmethod basic-cycles ((graph graph)) (let (cycles seen) (labels ((follow (node path used-edges) (push node seen) (dolist (edge (node-edges graph node)) (unless (member edge used-edges :test (edge-eq graph)) (dolist (neighbor (case (type-of graph) (graph (remove node edge)) (digraph (cdr (member node edge))))) (cond ((member neighbor path) (push (subseq path 0 (1+ (position neighbor path))) cycles)) (t (follow neighbor (cons neighbor path) (cons edge used-edges))))))))) (dolist (node (nodes graph)) (unless (member node seen) (follow node (list node) nil)))) (remove-duplicates cycles :test 'set-equal))) (defgeneric cycles (graph) (:documentation "Return all cycles of GRAPH (both basic and compound).")) (defmethod cycles ((graph graph)) (flet ((combine (c1 c2) (let (done) (reduce (lambda (acc el) (append (if (and (not done) (member el c1)) (progn (setf done t) (append (member el c1) (reverse (member el (reverse c1))))) (list el)) acc)) c2 :initial-value nil)))) (let ((basic-cycles (basic-cycles graph)) cycles) (loop :for cycle = (pop basic-cycles) :while cycle :do (push cycle cycles) (mapc (lambda (c) (push (combine c cycle) cycles)) (remove-if-not {intersection cycle} basic-cycles))) cycles))) (defgeneric minimum-spanning-tree (graph &optional tree) (:documentation "Return a minimum spanning tree of GRAPH. Prim's algorithm is used. Optional argument TREE may be used to specify an initial tree, otherwise a random node is used.")) (defmethod minimum-spanning-tree ((graph graph) &optional (tree (populate (make-instance 'graph) :nodes (list (random-elt (nodes graph)))))) (assert (connectedp graph) (graph) "~S is not connected" graph) (let ((copy (copy graph)) (total-nodes (length (nodes graph)))) (loop :until (= (length (nodes tree)) total-nodes) :do (let ((e (car (sort (remove-if-not {intersection (set-difference (nodes copy) (nodes tree))} (mapcan {node-edges copy} (nodes tree))) #'< :key {edge-value copy})))) (when e (add-edge tree e (edge-value graph e)) (delete-edge copy e)))) tree)) (defgeneric connected-groups-of-size (graph size) (:documentation "Return all connected node groups of SIZE in GRAPH.")) (defmethod connected-groups-of-size ((graph graph) size) ;; Note: this function doesn't work with hyper graphs (assert (> size 1) (size) "can't group less than two items") (let ((connected-groups (edges graph))) (loop :for i :from 2 :below size :do (setf connected-groups (mapcan (lambda (group) (mapcar {union group} (remove-if {subsetp _ group} (mapcan {node-edges graph} group)))) connected-groups))) (remove-duplicates connected-groups :test 'set-equal))) (defgeneric closedp (graph nodes) (:documentation "Return true if NODES are fully connected in GRAPH.")) (defmethod closedp ((graph graph) nodes) (block nil ;; Note: this function doesn't work with hyper graphs (map-combinations (lambda (pair) (unless (has-edge-p graph pair) (return nil))) nodes :length 2))) (defgeneric clustering-coefficient (graph) (:documentation "Fraction of connected triples which are closed.")) (defmethod clustering-coefficient ((graph graph)) (let ((triples (connected-groups-of-size graph 3))) (/ (length (remove-if-not {closedp graph} triples)) (length triples)))) (defgeneric cliques (graph) (:documentation "Return the maximal cliques of GRAPH. The Bron-Kerbosh algorithm is used.")) (defmethod cliques ((graph graph) &aux cliques) (labels ((bron-kerbosch (r p x) (if (and (null x) (null p)) (push r cliques) (loop :for v :in p :collect ;; TODO: use `degeneracy' ordering (let ((n (neighbors graph v))) (bron-kerbosch (union (list v) r) (intersection (set-difference p r) n) (intersection x n))) :do (setf p (remove v p) x (union (list v) x)))))) (bron-kerbosch nil (nodes graph) nil)) cliques) ;;; Shortest Path (defgeneric shortest-path (graph a b) (:documentation "Return the shortest path in GRAPH from A to B. GRAPH must be a directed graph. Dijkstra's algorithm is used.")) ;; TODO: needs to work for un-directed edges (defmethod shortest-path ((graph graph) a b &aux seen) (block nil ;; (car next) is leading node, (cdr next) is edge path (let ((next (list (list a)))) (loop :until (null next) :do (setf next (mapcan (lambda-bind ((from . rest)) (mapcan (lambda (edge) (if (case (type-of graph) (graph (member b edge)) (digraph (member b (cdr (member from edge))))) (return (reverse (cons edge rest))) (unless (member edge seen :test (edge-eq graph)) (push edge seen) (mapcar (lambda (n) (cons n (cons edge rest))) (case (type-of graph) (graph (remove from edge)) (digraph (cdr (member from edge)))))))) (node-edges graph from))) next)))))) ;;; Max Flow ;; - Must be a "network" (digraph in which each edge has a positive weight) ;; - Ford-Fulkerson is used (defgeneric residual (graph flow) (:documentation "Return the residual graph of GRAPH with FLOW. Each edge in the residual has a value equal to the original capacity minus the current flow, or equal to the negative of the current flow.")) (defmethod residual ((graph graph) flow) (flet ((flow-value (edge) (or (cdr (assoc edge flow :test (edge-eq graph))) 0))) (let ((residual (make-instance (type-of graph)))) (mapc (lambda (edge) (let ((left (- (edge-value graph edge) (flow-value edge)))) (when (not (zerop left)) (add-edge residual edge left))) (when (not (zerop (flow-value edge))) (add-edge residual (reverse edge) (flow-value edge)))) (edges graph)) residual))) (defgeneric add-paths (graph path1 path2) (:documentation "Return the combination of paths PATH1 and PATH2 through GRAPH. Each element of PATH has the form (cons edge value).")) (defmethod add-paths ((graph graph) path1 path2) (let ((comb (copy-tree path1))) (mapc (lambda-bind ((edge . value)) (if (assoc edge comb :test (edge-eq graph)) (setf (cdr (assoc edge comb :test (edge-eq graph))) (+ (cdr (assoc edge comb :test (edge-eq graph))) value)) (push (cons edge value) comb))) path2) comb)) (defmethod add-paths ((digraph digraph) path1 path2) "Return the combination of paths PATH1 and PATH2 through DIGRAPH. Each element of path has the form (cons edge value)." (let ((comb (copy-tree path1))) (mapc (lambda-bind ((edge . value)) (cond ((assoc edge comb :test (edge-eq digraph)) (setf (cdr (assoc edge comb :test (edge-eq digraph))) (+ (cdr (assoc edge comb :test (edge-eq digraph))) value))) ((assoc (reverse edge) comb :test (edge-eq digraph)) (setf (cdr (assoc (reverse edge) comb :test (edge-eq digraph))) (- (cdr (assoc edge comb :test (edge-eq digraph))) value))) (t (push (cons edge value) comb)))) path2) comb)) (defgeneric max-flow (graph from to) (:documentation "Return the maximum flow from FROM and TO in GRAPH. GRAPHS must be a network with numeric values of all edges. The Ford-Fulkerson algorithm is used.")) (defmethod max-flow ((digraph digraph) from to) (flet ((trim-path (path) (when path (let ((flow (apply #'min (mapcar #'cdr path)))) (mapcar (lambda (el) (cons (car el) flow)) path)))) (flow-value-into (flow node) (reduce #'+ (remove-if-not (lambda (el) (equal (lastcar (car el)) node)) flow) :key #'cdr))) (let ((from from) (to to) augment residual flow) (loop :do (setf residual (residual digraph flow)) ;; "augmenting path" is path through residual network in which each ;; edge has positive capacity (setf augment (trim-path (mapcar (lambda (edge) (cons edge (edge-value residual edge))) (shortest-path residual from to)))) :while augment :do ;; if ∃ an augmenting path, add it to the flow and repeat (setf flow (add-paths digraph flow augment))) (values flow (flow-value-into flow to))))) ;;; Min Cut ;; ;; Stoer, M. and Wagner, Frank. 1997. A Simple Min-Cut Algorithm. ;; Journal of the ACM ;; ;; Theorem: Let s,t ∈ (nodes G), let G' be the result of merging s and ;; t in G. Then (min-cut G) is equal to the minimum of the ;; min cut of s and t in G and (min-cut G'). ;; (defun weigh-cut (graph cut) (reduce #'+ (mapcar {edge-value graph} (remove-if-not (lambda (edge) (and (intersection edge (first cut)) (intersection edge (second cut)))) (edges graph))))) (defgeneric min-cut (graph) (:documentation "Return both the global min-cut of GRAPH and the weight of the cut.")) (defmethod min-cut ((graph graph)) (let ((g (copy graph)) (merged-nodes (mapcar (lambda (n) (list n n)) (nodes graph))) cuts-of-phase) (flet ((connection-weight (group node) ;; return the weight of edges between GROUP and NODE (reduce #'+ (mapcar {edge-value g} (remove-if-not {intersection group} (node-edges g node))))) (my-merge (a b) ;; merge in the graph (merge-nodes g a b) ;; update our merged nodes alist (setf (cdr (assoc a merged-nodes)) (append (cdr (assoc a merged-nodes)) (cdr (assoc b merged-nodes)))) (setq merged-nodes (remove-if (lambda (it) (eql (car it) b)) merged-nodes)))) (loop :while (> (length (nodes g)) 1) :do (let* ((a (list (random-elt (nodes g)))) (rest (remove (car a) (nodes g)))) (loop :while rest :do ;; grow A by adding the node most tightly connected to A (let ((new (car (sort rest #'> :key {connection-weight a})))) (setf rest (remove new rest)) (push new a))) ;; store the cut-of-phase (push (cons (connection-weight (cdr a) (car a)) (cdr (assoc (car a) merged-nodes))) cuts-of-phase) ;; merge two last added nodes (my-merge (first a) (second a)))) ;; return the minimum cut-of-phase (let* ((half (cdar (sort cuts-of-phase #'< :key #'car))) (cut (list half (set-difference (nodes graph) half)))) (values (sort cut #'< :key #'length) (weigh-cut graph cut)))))) ;;; Random graphs generation (defgeneric preferential-attachment-populate (graph nodes &key edge-vals) (:documentation ;; TODO: add optional argument for desired average degree "Add NODES to GRAPH using preferential attachment, return the new edges. Optionally assign edge values from those listed in EDGE-VALS.")) (defmethod preferential-attachment-populate ((graph graph) nodes &key edge-vals) (let ((degree-sum 0) (connections (make-array (* 2 (length nodes))))) (flet ((save-edge (from to) (incf degree-sum 2) (setf (aref connections (- degree-sum 2)) from) (setf (aref connections (- degree-sum 1)) to) (add-edge graph (list from to) (when edge-vals (pop edge-vals))))) (assert (not (= 1 (length nodes))) (nodes) "Can't preferentially attach a single node.") (when (null (nodes graph)) (save-edge (pop nodes) (pop nodes))) (mapc (lambda (n) (save-edge n (aref connections (random degree-sum)))) nodes) (edges-w-values graph)))) (defgeneric erdos-renyi-populate (graph m) (:documentation "Populate GRAPH with M edges in an Erdős–Rényi random graph model.")) (defmethod erdos-renyi-populate ((graph graph) m) (let* ((nodes (coerce (nodes graph) 'vector)) (num (length nodes))) (loop :until (= m 0) :do ;; NOTE: this naive approach will slow down drastically for ;; large nearly complete graphs (let ((a (aref nodes (random num))) (b (aref nodes (random num)))) (unless (or (= a b) (has-edge-p graph (list a b))) (add-edge graph (list a b)) (decf m))))) graph) (defun erdos-renyi-graph (n m) "Return an Erdős–Rényi graph with N nodes and M edges." (assert (and (not (< m 0)) (< m (/ (* n (1- n)) 2))) (n m) "an ~S-node graph can not have ~S edges" n m) (erdos-renyi-populate (populate (make-instance 'graph) :nodes (loop :for i :below n :collect i)) m)) (defun erdos-renyi-digraph (n m) "Return an Erdős–Rényi digraph with N nodes and M edges." (assert (and (not (< m 0)) (< m (* n (1- n)))) (n m) "an ~S-node digraph can not have ~S edges" n m) (erdos-renyi-populate (populate (make-instance 'digraph) :nodes (loop :for i :below n :collect i)) m)) (defgeneric edgar-gilbert-populate (graph p) (:documentation "Populate GRAPH including every possible edge with probability P.")) (defmethod edgar-gilbert-populate ((graph graph) p) (setf (edges graph) nil) (map-combinations (lambda (pair) ;; Note: needs refinement for hyper-graphs (when (< (random 1.0) p) (add-edge graph pair))) (nodes graph) :length 2) graph) (defmethod edgar-gilbert-populate ((digraph digraph) p) (setf (edges digraph) nil) (mapc (lambda (from) ;; Note: needs refinement for hyper-graphs (mapc (lambda (to) (when (< (random 1.0) p) (add-edge digraph (list from to)))) (remove from (nodes digraph)))) (nodes digraph)) digraph) (defun edgar-gilbert-graph (n p) (edgar-gilbert-populate (populate (make-instance 'graph) :nodes (loop :for i :below n :collect i)) p)) (defun edgar-gilbert-digraph (n p) (edgar-gilbert-populate (populate (make-instance 'digraph) :nodes (loop :for i :below n :collect i)) p)) ;;; Centrality (defgeneric farness (graph node) (:documentation "Sum of the distance from NODE to every other node in connected GRAPH.")) (defmethod farness ((graph graph) node) (assert (connectedp graph) (graph) "~S must be connected to calculate farness." graph) (reduce #'+ (mapcar [#'length {shortest-path graph node}] (remove node (nodes graph))))) (defgeneric closeness (graph node) (:documentation "Inverse of the `farness' for NODE in GRAPH.")) (defmethod closeness ((graph graph) node) (/ 1 ) (farness graph node)) (defgeneric betweenness (graph node) (:documentation "Fraction of shortest paths through GRAPH which pass through NODE. Fraction of node pairs (s,t) s.t. s and t ≠ NODE and the shortest path between s and t in GRAPH passes through NODE.")) (defmethod betweenness ((graph graph) node) (flet ((all-pairs (lst) (case (type-of graph) (graph (mapcan (lambda (n) (mapcar {list n} (cdr (member n lst)))) lst)) (digraph (mapcan (lambda (n) (mapcar {list n} (remove n lst))) lst))))) (let ((num 0) (denom 0)) (mapc (lambda-bind ((a b)) (when (member node (apply #'append (shortest-path graph a b))) (incf num)) (incf denom)) (all-pairs (remove node (nodes graph)))) (/ num denom)))) (defgeneric katz-centrality (graph node &key attenuation) (:documentation "Combined measure of number and nearness of nodes to NODE.")) (defmethod katz-centrality ((graph graph) node &key (attenuation 0.8)) (let ((cc (connected-component graph node))) (reduce #'+ (mapcar [{expt attenuation} #'length {shortest-path graph node}] (remove node cc))))) ;;; Degeneracy ;; ;; From the Wikipedia article on "Degeneracy (graph theory)". ;; (defgeneric degeneracy (graph) (:documentation "Return the degeneracy and k-cores of GRAPH. Also return the node ordering with optimal coloring number as an alist. The `car' of each element of the alist identifies k-cores and the `cdr' holds the nodes in the ordering.")) (defmethod degeneracy ((graph graph)) (let ((copy (copy graph)) (node-degree (make-hash-table)) (max-degree 0) (num-nodes 0) (k 0) (i 0) by-degree output) ;; initialize (mapc (lambda (n) (let ((degree (degree copy n))) (incf num-nodes) (setf (gethash n node-degree) degree) (setf max-degree (max max-degree degree)))) (nodes copy)) (setf by-degree (make-array (1+ max-degree) :initial-element nil)) (maphash (lambda (node degree) (push node (aref by-degree degree))) node-degree) ;; reduction (dotimes (n num-nodes (values k output)) (setf i 0) (loop :until (aref by-degree i) :do (incf i)) ;; create alist element for the new core (when (< k (setf k (max k i))) (push (list k) output)) ;; drop a node and demote all neighbors (let ((node (pop (aref by-degree i)))) (push node (cdr (assoc k output))) (mapc (lambda (node) (setf (aref by-degree (gethash node node-degree)) (remove node (aref by-degree (gethash node node-degree)))) (decf (gethash node node-degree)) (push node (aref by-degree (gethash node node-degree)))) (prog1 (remove-duplicates (remove node (neighbors copy node))) (delete-node copy node))))))) (defgeneric k-cores (graph) (:documentation "Return the k-cores of GRAPH.")) (defmethod k-cores ((graph graph)) (multiple-value-bind (k cores) (degeneracy graph) (declare (ignorable k)) cores)) graph-20180131-git/json.lisp000066400000000000000000000146501322077423300155100ustar00rootroot00000000000000;;; graph.lisp --- because its easier to write than to learn such a library ;; Copyright (C) Eric Schulte 2013 ;; Licensed under the Gnu Public License Version 3 or later ;;; Commentary ;; Helper function for serializing Graphs to JSON objects and reading ;; JSON objects back into graphs. The JSON syntax for a graph is ;; compatible with the JavaScript d3 visualization library, allowing ;; for interactive viewing of graphs in the browser. ;; See [d3](http://d3js.org/) ;; (specifically [d3-force](http://bl.ocks.org/4062045)) for more. ;;; Code: (defpackage #:graph/json (:use :common-lisp :alexandria :metabang-bind :named-readtables :curry-compose-reader-macros :graph :yason) (:export :to-json :from-json :to-d3 :from-d3 :to-html)) (in-package :graph/json) (in-readtable :curry-compose-reader-macros) (defun json-to-plist (input) "Parse string or stream INPUT into a plist." (let ((yason:*parse-object-key-fn* (lambda (el) (intern (string-upcase el) "KEYWORD"))) (yason:*parse-object-as* :plist)) (yason:parse input))) ;;; JSON import and export (defmethod yason:encode ((symbol symbol) &optional (stream *standard-output*)) (yason:encode (string-downcase (symbol-name symbol)) stream)) (defgeneric to-json (graph &key stream node-fn edge-fn) (:documentation "Write a JSON encoding of GRAPH to STREAM.")) (defmethod to-json ((graph graph) &key (stream *standard-output*) node-fn edge-fn) (let ((plist (to-plist graph :node-fn node-fn :edge-fn edge-fn))) (yason:encode (plist-hash-table (list :nodes (mapcar #'plist-hash-table (getf plist :nodes)) :edges (mapcar #'plist-hash-table (getf plist :edges)))) stream))) (defun intern-string-nodes (plist) (list :nodes (mapcar [{list :name} #'intern #'string-upcase {getf _ :name}] (getf plist :nodes)) :edges (getf plist :edges))) (defmethod from-json ((graph graph) input) "Parse string or stream INPUT into GRAPH." (from-plist graph (intern-string-nodes (json-to-plist input)))) ;;; plist and D3 conversion (defun plist-to-d3 (plist) "Convert plist graph encoding PLIST to D3 format. Note that D3 only handles 2-node edges, so extra nodes in edges will be silently dropped." (list :nodes (getf plist :nodes) :links (mapcar (lambda (edge) (let ((edge (getf edge :edge)) (value (getf edge :value))) (list :source (first edge) :target (second edge) :value value))) (getf plist :edges)))) (defun d3-to-plist (plist) "Convert D3 format PLIST to graph encoding." (list :nodes (mapcar [{list :name} #'intern #'string-upcase {getf _ :name}] (getf plist :nodes)) :edges (mapcar (lambda (edge) (list :edge (list (getf edge :source) (getf edge :target)) :value (getf edge :value))) (getf plist :links)))) ;;; D3 format JSON import and export (defgeneric to-d3 (graph &key stream group-fn) (:documentation "Return a JSON encoding of GRAPH formatted for D3. Edges should have numeric values which d3 will translate into their width. Optional keyword argument GROUP-FN should be a function from nodes to group numbers.")) (defmethod to-d3 ((graph graph) &key (stream *standard-output*) group-fn) (let* ((plist (plist-to-d3 (if group-fn (to-plist graph :node-fn [{list :group} group-fn]) (to-plist graph)))) (hash (plist-hash-table (list :nodes (mapcar #'plist-hash-table (getf plist :nodes)) :links (mapcar #'plist-hash-table (getf plist :links)))))) (if stream (yason:encode hash stream) (with-output-to-string (out) (yason:encode hash out))))) (defgeneric from-d3 (graph input) (:documentation "Parse a D3 format string or stream INPUT into GRAPH.")) (defmethod from-d3 ((graph graph) input) (from-plist graph (d3-to-plist (json-to-plist input)))) (defgeneric to-html (graph &key stream group-fn) (:documentation "Write GRAPH to an HTML file. The resulting HTML file will display an interactive version of GRAPH. Uses `to-d3' to first encode the graph as JSON which is embedded in the HTML page.")) (defmethod to-html ((graph graph) &key (stream *standard-output*) group-fn) (format stream d3-html (to-d3 graph :stream nil :group-fn group-fn))) (defvar d3-html " ") graph-20180131-git/matrix-test.lisp000066400000000000000000000652321322077423300170220ustar00rootroot00000000000000;;; test/graph-matrix.lisp --- tests for the graph matrix library ;; Copyright (C) Eric Schulte and Tom Dye 2013 ;; Licensed under the Gnu Public License Version 3 or later ;;; Code: (defpackage #:graph/matrix-test (:use :common-lisp :alexandria :metabang-bind :graph :graph/matrix :stefil :named-readtables :curry-compose-reader-macros) (:export :test)) (in-package :graph/matrix-test) (in-readtable :curry-compose-reader-macros) (defsuite test) (in-suite test) (defvar *graph* nil "Variable for use in graph tests.") (defixture basic-graph (:setup (setf *graph* (populate (make-instance 'graph) :nodes '(a b c d e f) :edges '((a b) (b c) (c d) (d e) (e c) (e f) (f b))))) (:teardown (setf *graph* nil))) ;;; Structural Models in Anthropology, Hage and Harary 1983, Figure ;;; 5.2, p. 96 (defixture hh-5-2 (:setup (setf *graph* (populate (make-instance 'graph) :nodes '(1 2 3 4) :edges '((1 2) (1 3) (1 4) (2 3) (3 4))))) (:teardown (setf *graph* nil))) ;;; Structural Models in Anthropology, Hage and Harary 1983, Figure ;;; 5.3, p. 97 (defixture hh-5-3 (:setup (setf *graph* (populate (make-instance 'digraph) :nodes '(1 2 3 4) :edges '((1 3) (1 4) (2 1) (2 3) (3 2) (4 3) (4 1))))) (:teardown (setf *graph* nil))) ;;; Structural Models in Anthropology, Hage and Harary 1983, Figure ;;; 5.10, p. 107 (defixture hh-5-10 (:setup (setf *graph* (populate (make-instance 'digraph) :nodes '(1 2 3 4) :edges '((1 2) (2 3) (2 4) (3 2) (3 4))))) (:teardown (setf *graph* nil))) ;;; Exchange in Oceania: A Graph Theoretic Analysis, Hage and Harary ;;; 1991, Figure 4.5, p. 121 (defixture hh-4-5 (:setup (setf *graph* (populate (make-instance 'digraph) :nodes '(1 2 3 4) :edges '((1 2) (1 3) (1 4) (2 3) (3 1) (4 3))))) (:teardown (setf *graph* nil))) ;;; Structural Models in Anthropology, Hage and Harary 1983, Figure ;;; 5.11, p. 110 (defixture hh-5-11 (:setup (setf *graph* (populate (make-instance 'digraph) :nodes '(1 2 3 4 5) :edges '((1 2) (1 3) (2 3) (3 1) (4 3) (5 4) (5 1))))) (:teardown (setf *graph* nil))) ;;; Structural Models in Anthropology, Hage and Harary 1983, Figure ;;; 4.18, p. 86. 2' -> 22, 2" -> 222, etc. (defixture hh-4-18 (:setup (setf *graph* (populate (make-instance 'digraph) :nodes '(0 1 11 2 22 222 3 33) :edges '((0 1) (0 11) (1 2) (1 22) (1 222) (1 3) (1 33) (11 2) (11 22) (11 222) (11 3) (11 33) (2 22) (2 222) (2 3) (2 33) (22 2) (22 222) (22 3) (22 33) (222 2) (222 22) (222 3) (222 33))))) (:teardown (setf *graph* nil))) (defixture relation (:setup (setf *graph* (populate (make-instance 'digraph) :nodes '(a b c d) :edges '((a c) (b b) (c c) (c b) (c a) (d a) (d c))))) (:teardown (setf *graph* nil))) (defixture digraph (:setup (setf *graph* (populate (make-instance 'digraph) :nodes '(a b c d) :edges '((a c) (a d) (c b) (c a) (d c))))) (:teardown (setf *graph* nil))) (defixture graph (:setup (setf *graph* (populate (make-instance 'digraph) :nodes '(a b c d) :edges '((a c) (a d) (b c) (c b) (c a) (c d) (d c) (d a))))) (:teardown (setf *graph* nil))) (defixture oriented-graph (:setup (setf *graph* (populate (make-instance 'digraph) :nodes '(a b c d) :edges '((a d) (b c) (c a) (c d))))) (:teardown (setf *graph* nil))) (defixture similarity-relation (:setup (setf *graph* (populate (make-instance 'digraph) :nodes '(a b c d) :edges '((a a) (a c) (a d) (b b) (b c) (c c) (c a) (c b) (c d) (d d) (d a) (d c))))) (:teardown (setf *graph* nil))) (defixture equivalence-relation (:setup (setf *graph* (populate (make-instance 'digraph) :nodes '(a b c d) :edges '((a a) (a c) (a d) (b b) (c c) (c a) (c d) (d d) (d c) (d a))))) (:teardown (setf *graph* nil))) (defixture partial-order (:setup (setf *graph* (populate (make-instance 'digraph) :nodes '(a b c d) :edges '((a c) (a d) (b c) (d c))))) (:teardown (setf *graph* nil))) (defixture complete-order (:setup (setf *graph* (populate (make-instance 'digraph) :nodes '(a b c d) :edges '((a b) (a c) (a d) (b c) (d b) (d c))))) (:teardown (setf *graph* nil))) (defixture tournament (:setup (setf *graph* (populate (make-instance 'digraph) :nodes '(a b c d) :edges '((a c) (a d) (b a) (c b) (d b) (d c))))) (:teardown (setf *graph* nil))) (defixture parity-relation (:setup (setf *graph* (populate (make-instance 'digraph) :nodes '(a b c d) :edges '((a c) (a d) (c a) (c d) (d a) (d c))))) (:teardown (setf *graph* nil))) (defixture antiequivalence-relation (:setup (setf *graph* (populate (make-instance 'digraph) :nodes '(a b c d) :edges '((a d) (b a) (c b) (d c))))) (:teardown (setf *graph* nil))) (defixture antiparity-relation (:setup (setf *graph* (populate (make-instance 'digraph) :nodes '(a b c d) :edges '((a a) (a d) (b b) (b a) (c c) (c b) (d d) (d c))))) (:teardown (setf *graph* nil))) ;;; Tests ;;; Test simple functions (deftest same-size-p () (let ((f1 (make-zeros-matrix (make-instance 'fast-matrix) 2 4)) (l1 (make-zeros-matrix (make-instance 'matrix) 2 4)) (f2 (make-zeros-matrix (make-instance 'fast-matrix) 4 2)) (l2 (make-zeros-matrix (make-instance 'matrix) 4 2)) (l3 (make-zeros-matrix (make-instance 'matrix) 2 4)) (f3 (make-zeros-matrix (make-instance 'fast-matrix) 2 4))) (is (not (matrix-same-size-p f1 f2))) (is (not (matrix-same-size-p l1 l2))) (is (not (matrix-same-size-p f1 l2))) (is (matrix-same-size-p f1 f3)) (is (matrix-same-size-p l1 l3)) (is (matrix-same-size-p l1 f1)) (is (matrix-same-size-p f1 l3)))) (deftest symmetric-p () (with-fixture hh-5-10 (let ((m1 (make-identity-matrix (make-instance 'matrix) 3)) (f1 (make-identity-matrix (make-instance 'fast-matrix) 3)) (m2 (to-adjacency-matrix *graph* (make-instance 'matrix))) (f2 (to-adjacency-matrix *graph* (make-instance 'fast-matrix)))) (is (matrix-symmetric-p m1)) (is (matrix-symmetric-p f1)) (is (not (matrix-symmetric-p m2))) (is (not (matrix-symmetric-p f2)))))) ;;; Test whether matrix entry comparisons work as expected (deftest matrix-entries-are-not-different () (with-fixture basic-graph (let ((m (to-adjacency-matrix *graph* (make-instance 'matrix)))) (is (not (matrix-entries-different-p m m)))))) (deftest fast-matrix-entries-are-not-different () (with-fixture basic-graph (let ((m (to-adjacency-matrix *graph* (make-instance 'fast-matrix)))) (is (not (matrix-entries-different-p m m)))))) (deftest matrix-entries-are-different () (let ((z (make-zeros-matrix (make-instance 'matrix) 3 3)) (u (make-universal-matrix (make-instance 'matrix) 3 3))) (is (matrix-entries-different-p u z)))) (deftest fast-matrix-entries-are-different () (let ((z (make-zeros-matrix (make-instance 'fast-matrix) 3 3)) (u (make-universal-matrix (make-instance 'fast-matrix) 3 3))) (is (matrix-entries-different-p u z)))) (deftest matrix-entries-are-different-sizes () (let ((z (make-zeros-matrix (make-instance 'matrix) 3 4)) (u (make-universal-matrix (make-instance 'matrix) 3 3))) (is (= 1 (matrix-entries-different-p u z))))) (deftest fast-matrix-entries-are-different-sizes () (let ((z (make-zeros-matrix (make-instance 'fast-matrix) 3 4)) (u (make-universal-matrix (make-instance 'fast-matrix) 3 3))) (is (= 1 (matrix-entries-different-p u z))))) (deftest lisp-and-fast-matrix-entries-are-not-different () (let ((f (make-zeros-matrix (make-instance 'fast-matrix) 3 3)) (l (make-zeros-matrix (make-instance 'matrix) 3 3))) (is (not (matrix-entries-different-p f l))))) ;;; Tests for comparability of lisp and fast matrix operations (deftest lisp-vs-fast-difference () (let ((f0 (make-zeros-matrix (make-instance 'fast-matrix) 3 3)) (f1 (make-universal-matrix (make-instance 'fast-matrix) 3 3)) (l0 (make-zeros-matrix (make-instance 'matrix) 3 3)) (l1 (make-universal-matrix (make-instance 'matrix) 3 3))) (is (not (matrix-entries-different-p (graph/matrix::matrix-difference f0 f1) (graph/matrix::matrix-difference l0 l1)))))) (deftest lisp-vs-fast-sum () (let ((f0 (make-zeros-matrix (make-instance 'fast-matrix) 3 3)) (f1 (make-universal-matrix (make-instance 'fast-matrix) 3 3)) (l0 (make-zeros-matrix (make-instance 'matrix) 3 3)) (l1 (make-universal-matrix (make-instance 'matrix) 3 3))) (is (not (matrix-entries-different-p (graph/matrix::matrix-sum f0 f1) (graph/matrix::matrix-sum l0 l1)))))) (deftest lisp-vs-fast-elementwise-product () (let ((f0 (make-zeros-matrix (make-instance 'fast-matrix) 3 3)) (f1 (make-universal-matrix (make-instance 'fast-matrix) 3 3)) (l0 (make-zeros-matrix (make-instance 'matrix) 3 3)) (l1 (make-universal-matrix (make-instance 'matrix) 3 3))) (is (not (matrix-entries-different-p (graph/matrix::matrix-elementwise-product f0 f1) (graph/matrix::matrix-elementwise-product l0 l1)))))) (deftest lisp-vs-fast-sum-boolean () (let ((f0 (make-zeros-matrix (make-instance 'fast-matrix) 3 3)) (f1 (make-universal-matrix (make-instance 'fast-matrix) 3 3)) (l0 (make-zeros-matrix (make-instance 'matrix) 3 3)) (l1 (make-universal-matrix (make-instance 'matrix) 3 3))) (is (not (matrix-entries-different-p (graph/matrix::matrix-sum f0 f1 :boolean t) (graph/matrix::matrix-sum l0 l1 :boolean t)))))) (deftest lisp-vs-fast-product () (let ((f0 (make-zeros-matrix (make-instance 'fast-matrix) 3 3)) (f1 (make-universal-matrix (make-instance 'fast-matrix) 3 3)) (l0 (make-zeros-matrix (make-instance 'matrix) 3 3)) (l1 (make-universal-matrix (make-instance 'matrix) 3 3))) (is (not (matrix-entries-different-p (graph/matrix::matrix-product f0 f1) (graph/matrix::matrix-product l0 l1)))))) (deftest lisp-vs-fast-transpose () (let ((f0 (make-zeros-matrix (make-instance 'fast-matrix) 3 3)) (f1 (make-universal-matrix (make-instance 'fast-matrix) 3 3)) (l0 (make-zeros-matrix (make-instance 'matrix) 3 3)) (l1 (make-universal-matrix (make-instance 'matrix) 3 3))) (is (not (matrix-entries-different-p (matrix-transpose (graph/matrix::matrix-elementwise-product f0 f1)) (matrix-transpose (graph/matrix::matrix-elementwise-product l0 l1))))))) (deftest lisp-vs-fast-power-0 () (let ((f0 (make-zeros-matrix (make-instance 'fast-matrix) 3 3)) (f1 (make-universal-matrix (make-instance 'fast-matrix) 3 3)) (l0 (make-zeros-matrix (make-instance 'matrix) 3 3)) (l1 (make-universal-matrix (make-instance 'matrix) 3 3))) (is (not (matrix-entries-different-p (graph/matrix::matrix-power (graph/matrix::matrix-elementwise-product f0 f1) 0) (graph/matrix::matrix-power (graph/matrix::matrix-elementwise-product l0 l1) 0)))))) (deftest lisp-vs-fast-power-1 () (let ((f0 (make-zeros-matrix (make-instance 'fast-matrix) 3 3)) (f1 (make-universal-matrix (make-instance 'fast-matrix) 3 3)) (l0 (make-zeros-matrix (make-instance 'matrix) 3 3)) (l1 (make-universal-matrix (make-instance 'matrix) 3 3))) (is (not (matrix-entries-different-p (graph/matrix::matrix-power (graph/matrix::matrix-elementwise-product f0 f1) 1) (graph/matrix::matrix-power (graph/matrix::matrix-elementwise-product l0 l1) 1)))))) (deftest lisp-vs-fast-power-2 () (let ((f0 (make-zeros-matrix (make-instance 'fast-matrix) 3 3)) (f1 (make-universal-matrix (make-instance 'fast-matrix) 3 3)) (l0 (make-zeros-matrix (make-instance 'matrix) 3 3)) (l1 (make-universal-matrix (make-instance 'matrix) 3 3))) (is (not (matrix-entries-different-p (graph/matrix::matrix-power (graph/matrix::matrix-elementwise-product f0 f1) 2) (graph/matrix::matrix-power (graph/matrix::matrix-elementwise-product l0 l1) 2)))))) (deftest lisp-vs-fast-power-3 () (let ((f0 (make-zeros-matrix (make-instance 'fast-matrix) 3 3)) (f1 (make-universal-matrix (make-instance 'fast-matrix) 3 3)) (l0 (make-zeros-matrix (make-instance 'matrix) 3 3)) (l1 (make-universal-matrix (make-instance 'matrix) 3 3))) (is (not (matrix-entries-different-p (graph/matrix::matrix-power (graph/matrix::matrix-elementwise-product f0 f1) 3) (graph/matrix::matrix-power (graph/matrix::matrix-elementwise-product l0 l1) 3)))))) (deftest lisp-vs-fast-copy () (let ((f (make-zeros-matrix (make-instance 'fast-matrix) 3 3)) (l (make-zeros-matrix (make-instance 'matrix) 3 3))) (is (not (matrix-entries-different-p (matrix-copy f) (matrix-copy l)))))) ;;; Tests comparing matrix and fast-matrix results (deftest adjacency-matrix-vs-fast-matrix () (with-fixture basic-graph (let ((m (to-adjacency-matrix *graph* (make-instance 'matrix))) (f (to-adjacency-matrix *graph* (make-instance 'fast-matrix)))) (is (not (matrix-entries-different-p m f)))))) (deftest adjacency-matrix-vs-fast-matrix-digraph () (with-fixture hh-4-18 (let ((m (to-adjacency-matrix *graph* (make-instance 'matrix))) (f (to-adjacency-matrix *graph* (make-instance 'fast-matrix)))) (is (not (matrix-entries-different-p m f)))))) (deftest reachability-matrix-vs-fast-matrix () (with-fixture basic-graph (let ((m (to-reachability-matrix *graph* (make-instance 'matrix))) (f (to-reachability-matrix *graph* (make-instance 'fast-matrix)))) (is (not (matrix-entries-different-p m f)))))) (deftest reachablep-lisp-vs-fast () (with-fixture hh-5-10 (let ((m (to-reachability-matrix *graph* (make-instance 'matrix))) (f (to-reachability-matrix *graph* (make-instance 'fast-matrix)))) (is (and (reachablep *graph* m 1 2) (reachablep *graph* f 1 2))) (is (and (reachablep *graph* m 2 3) (reachablep *graph* f 2 3))) (is (not (or (reachablep *graph* f 2 1) (reachablep *graph* f 2 1))))))) (deftest reachable-from-lisp-vs-fast () (with-fixture hh-5-10 (let ((m (to-reachability-matrix *graph* (make-instance 'matrix))) (f (to-reachability-matrix *graph* (make-instance 'fast-matrix)))) (is (equal (reachable-from *graph* m 1) (reachable-from *graph* f 1))) (is (equal (reachable-from *graph* m 2) (reachable-from *graph* f 2))) (is (equal (reachable-from *graph* m 3) (reachable-from *graph* f 3))) (is (equal (reachable-from *graph* m 4) (reachable-from *graph* f 4))) (is (equal (reachable-from *graph* m 1) '(1 2 3 4))) (is (equal (reachable-from *graph* m 2) '(2 3 4))) (is (equal (reachable-from *graph* m 3) '(2 3 4))) (is (equal (reachable-from *graph* m 4) '(4)))))) (deftest strong-component-matrix-vs-fast-matrix () (with-fixture hh-5-10 (let ((m (to-reachability-matrix *graph* (make-instance 'matrix))) (f (to-reachability-matrix *graph* (make-instance 'fast-matrix)))) (is (not (matrix-entries-different-p (to-strong-component-matrix m) (to-strong-component-matrix f))))))) (deftest strong-component-of-lisp-vs-fast-matrix () (with-fixture hh-5-10 (let ((m (to-strong-component-matrix (to-reachability-matrix *graph* (make-instance 'matrix)))) (f (to-strong-component-matrix (to-reachability-matrix *graph* (make-instance 'fast-matrix))))) (is (equal (strong-component-of 1 *graph* m) (strong-component-of 1 *graph* f))) (is (equal (strong-component-of 2 *graph* m) (strong-component-of 2 *graph* f))) (is (equal (strong-component-of 3 *graph* m) (strong-component-of 3 *graph* f))) (is (equal (strong-component-of 4 *graph* m) (strong-component-of 4 *graph* f)))))) (deftest distance-matrix-vs-fast-matrix () (with-fixture basic-graph (let ((m (to-distance-matrix *graph* (make-instance 'matrix))) (f (to-distance-matrix *graph* (make-instance 'fast-matrix)))) (is (not (matrix-entries-different-p m f)))))) (deftest distance-from-to-lisp-vs-fast-matrix () (with-fixture basic-graph (let ((m (to-distance-matrix *graph* (make-instance 'matrix))) (f (to-distance-matrix *graph* (make-instance 'fast-matrix)))) (is (= (distance-from-to *graph* m 'a 'b) (distance-from-to *graph* f 'a 'b))) (is (= (distance-from-to *graph* m 'a 'c) (distance-from-to *graph* f 'a 'c))) (is (= (distance-from-to *graph* m 'a 'd) (distance-from-to *graph* f 'a 'd))) (is (= (distance-from-to *graph* m 'a 'e) (distance-from-to *graph* f 'a 'e))) (is (= (distance-from-to *graph* m 'a 'f) (distance-from-to *graph* f 'a 'f)))))) ;;; Tests comparing results of lisp matrix routines to Hage and Harary's book (deftest digraph-and-adjacency-matrix () (let ((m (make-instance 'matrix))) (setf (graph/matrix::self m) (make-array '(4 4) :element-type 'fixnum :initial-contents '((0 0 1 1) (1 0 1 0) (0 1 0 0) (1 0 1 0)))) (with-fixture hh-5-3 (is (not (matrix-entries-different-p (to-adjacency-matrix *graph* (make-instance 'matrix)) m)))))) (deftest digraph-and-reachability-matrix () (let ((m (make-instance 'matrix))) (setf (graph/matrix::self m) (make-array '(4 4) :element-type 'fixnum :initial-contents '((1 1 1 1)(0 1 1 1)(0 1 1 1)(0 0 0 1)))) (with-fixture hh-5-10 (is (not (matrix-entries-different-p (to-reachability-matrix *graph* (make-instance 'matrix)) m)))))) ;;; This is the matrix R2 on p. 126 of Exchange in Oceania: A Graph ;;; Theoretic Analysis by Per Hage and Frank Harary (deftest digraph-and-reachability-matrix-with-limit-2 () (let ((m (make-instance 'matrix))) (setf (graph/matrix::self m) (make-array '(4 4) :element-type 'fixnum :initial-contents '((1 1 1 1)(1 1 1 0)(1 1 1 1)(1 0 1 1)))) (with-fixture hh-4-5 (is (not (matrix-entries-different-p (to-reachability-matrix *graph* (make-instance 'matrix) :limit 2) m)))))) (deftest digraph-and-distance-matrix () (let* ((m (make-instance 'matrix)) (i (graph/matrix::infinite m))) (setf (graph/matrix::self m) (make-array '(5 5) :initial-contents `((0 1 1 ,i ,i) (2 0 1 ,i ,i) (1 2 0 ,i ,i) (2 3 1 0 ,i) (1 2 2 1 0)))) (with-fixture hh-5-11 (let ((d (to-distance-matrix *graph* (make-instance 'matrix)))) (is (not (matrix-entries-different-p d m))))))) (deftest digraph-and-strong-component-matrix () (let ((m (make-instance 'matrix))) (setf (graph/matrix::self m) (make-array '(8 8) :element-type 'fixnum :initial-contents '((1 0 0 0 0 0 0 0) (0 1 0 0 0 0 0 0) (0 0 1 0 0 0 0 0) (0 0 0 1 1 1 0 0) (0 0 0 1 1 1 0 0) (0 0 0 1 1 1 0 0) (0 0 0 0 0 0 1 0) (0 0 0 0 0 0 0 1)))) (with-fixture hh-4-18 (is (not (matrix-entries-different-p (to-strong-component-matrix (to-reachability-matrix *graph* (make-instance 'matrix))) m)))))) ;;; Tests of Peirce relations (deftest relation-test () (with-fixture relation (is (not (relational-structure *graph* (make-instance 'matrix)))))) (deftest digraph-test () (with-fixture digraph (is (relational-structure *graph* (make-instance 'matrix)) "digraph"))) (deftest graph-test () (with-fixture graph (is (relational-structure *graph* (make-instance 'matrix)) "graph"))) (deftest oriented-graph-test () (with-fixture oriented-graph (is (relational-structure *graph* (make-instance 'matrix)) "oriented graph"))) (deftest similarity-relation-test () (with-fixture similarity-relation (is (relational-structure *graph* (make-instance 'matrix)) "similarity relation"))) (deftest equivalence-relation-test () (with-fixture equivalence-relation (is (relational-structure *graph* (make-instance 'matrix)) "equivalence relation"))) (deftest complete-order-test () (with-fixture complete-order (is (relational-structure *graph* (make-instance 'matrix)) "complete order"))) (deftest tournament-test () (with-fixture tournament (is (relational-structure *graph* (make-instance 'matrix)) "tournament"))) (deftest parity-relation-test () (with-fixture parity-relation (is (relational-structure *graph* (make-instance 'matrix)) "parity relation"))) (deftest antiequivalence-relation-test () (with-fixture antiequivalence-relation (is (relational-structure *graph* (make-instance 'matrix)) "antiequivalence relation"))) (deftest antiparity-relation-test () (with-fixture antiparity-relation (is (relational-structure *graph* (make-instance 'matrix)) "antiparity relation"))) graph-20180131-git/matrix.lisp000066400000000000000000000650331322077423300160440ustar00rootroot00000000000000;;; graph-matrix.lisp --- build and manipulate matrix graph representations ;; Copyright (C) Eric Schulte and Tom Dye 2013 ;; Licensed under the Gnu Public License Version 3 or later ;;; Commentary ;; Functions for manipulating matrix graph representations. ;;; Code: (defpackage #:graph/matrix (:use :common-lisp :alexandria :metabang-bind :named-readtables :curry-compose-reader-macros :graph :fl.function) ;; shadow functions defined in alexandria, fl.function, and graph (:shadow :copy :factorial :standard-deviation :variance :median :mean :degree) (:export :matrix :fast-matrix :matrix-ref :matrix-n-rows :matrix-n-cols :matrix-same-size-p :matrix-symmetric-p :matrix-entries-different-p :matrix-copy :matrix-transpose :make-universal-matrix :make-identity-matrix :make-zeros-matrix :to-adjacency-matrix :to-reachability-matrix :reachablep :reachable-from :to-strong-component-matrix :strong-component-of :to-distance-matrix :distance-from-to :reflexivep :irreflexivep :symmetricp :asymmetricp :transitivep :intransitivep :completep :relational-structure :infinite :infinitep)) (in-package :graph/matrix) (in-readtable :curry-compose-reader-macros) (defclass matrix () ((self :initarg :self :accessor self :initform nil))) (defclass fast-matrix (matrix) ()) (defgeneric infinite (matrix) (:documentation "Return the most-positive value for the element type of MATRIX.")) (defmethod infinite ((matrix matrix)) most-positive-fixnum) (defmethod infinite ((matrix fast-matrix)) most-positive-single-float) (defgeneric infinitep (value matrix) (:documentation "Non-nil if VALUE is the most-positive value that can be held in MATRIX.")) (defmethod infinitep (value (matrix matrix)) (= value (infinite matrix))) (defgeneric matrix-ref (matrix row col) (:documentation "Return the value at ROW and COL in MATRIX.")) (defmethod matrix-ref ((matrix matrix) row col) (aref (self matrix) row col)) (defmethod matrix-ref ((fm fast-matrix) row col) (fl.function::mref (self fm) row col)) (defgeneric (setf matrix-ref) (new matrix row col) (:documentation "Make matrix-ref setf-able.")) (defmethod (setf matrix-ref) (new (matrix matrix) row col) (setf (aref (self matrix) row col) new)) (defmethod (setf matrix-ref) (new (fm fast-matrix) row col) (setf (fl.function::mref (self fm) row col) new)) (defgeneric matrix-n-rows (matrix) (:documentation "Return the number of rows in MATRIX.")) (defmethod matrix-n-rows ((matrix matrix)) (if (self matrix) (array-dimension (self matrix) 0) 0)) (defmethod matrix-n-rows ((matrix fast-matrix)) (if (self matrix) (fl.function::nrows (self matrix)) 0)) (defgeneric matrix-n-cols (matrix) (:documentation "Return the number of columns in MATRIX.")) (defmethod matrix-n-cols ((matrix matrix)) (if (self matrix) (array-dimension (self matrix) 1) 0)) (defmethod matrix-n-cols ((matrix fast-matrix)) (if (self matrix) (fl.function::ncols (self matrix)) 0)) (defun matrix-same-size-p (m1 m2) "Return t if matrix M1 has the same number of rows and columns as matrix M2, nil otherwise." (and (= (matrix-n-rows m1) (matrix-n-rows m2)) (= (matrix-n-cols m1) (matrix-n-cols m2)))) (defun matrix-entries-different-p (m1 m2) "Returns nil if the entries in matrix M1 and matrix M2 do not differ from one another. Returns 1 if the sizes of matrix M1 and matrix M2 differ. Otherwise, returns a list of lists containing discrepant entries. " (let ((result)) (if (matrix-same-size-p m1 m2) (let ((m (matrix-n-rows m1)) (n (matrix-n-cols m1))) (loop :for i :from 0 :below m :do (loop :for j :from 0 :below n :do (unless (= (matrix-ref m1 i j) (matrix-ref m2 i j)) (push (list i j) result)))) (when result (reverse result))) (setf result 1)) result)) (defun matrix-symmetric-p (matrix) "Return t if matrix MATRIX is symmetric, nil otherwise." (not (matrix-entries-different-p matrix (matrix-transpose matrix)))) (defgeneric matrix-copy (matrix) (:documentation "Return a copy of MATRIX.")) (defmethod matrix-copy ((matrix matrix)) (let* ((m (matrix-n-rows matrix)) (n (matrix-n-cols matrix)) (result (make-zeros-matrix (make-instance 'matrix) m n))) (when (self matrix) (loop :for i :from 0 :below m :do (loop :for j :from 0 :below n :do (setf (matrix-ref result i j) (matrix-ref matrix i j))))) result)) (defmethod matrix-copy ((fm fast-matrix)) (let ((result (make-instance 'fast-matrix))) (when (self fm) (setf (self result) (fl.function::copy (self fm)))) result)) (defgeneric matrix-sum (m1 m2 &key boolean) (:documentation "Return the result of adding matrix M1 and matrix M2. M1 and M2 must be the same size. If BOOLEAN is non-nil, then use boolean arithmetic, where 1+1=1.")) (defmethod matrix-sum ((m1 matrix) (m2 matrix) &key boolean) (and (matrix-same-size-p m1 m2) (let* ((m (matrix-n-rows m1)) (n (matrix-n-cols m1)) (result (make-zeros-matrix (make-instance 'matrix) m n)) (zero 0) (one 1)) (declare (type fixnum zero)) (declare (type fixnum one)) (loop :for i :from 0 :below m :do (loop :for j :from 0 :below n :do (setf (matrix-ref result i j) (if boolean (if (> (+ (matrix-ref m1 i j) (matrix-ref m2 i j)) 0) one zero) (+ (matrix-ref m1 i j) (matrix-ref m2 i j)))))) result))) (defmethod matrix-sum ((m1 fast-matrix) (m2 fast-matrix) &key boolean) (when (matrix-same-size-p m1 m2) (let ((result (make-instance 'fast-matrix))) (setf (self result) (fl.function::m+ (self m1) (self m2))) (when boolean (let ((m (matrix-n-rows result)) (n (matrix-n-cols result)) (one 1.0s0)) (declare (type single-float one)) (loop :for i :from 0 :below m :do (loop :for j :from 0 :below n :do (if (> (matrix-ref result i j) 0) (setf (matrix-ref result i j) one)))))) result))) (defgeneric matrix-difference (m1 m2) (:documentation "Return the result of subtracting M2 from M1. M1 and M2 must be the same size.")) (defmethod matrix-difference ((m1 matrix) (m2 matrix)) (and (matrix-same-size-p m1 m2) (let ((result (matrix-copy m1)) (m (matrix-n-rows m1)) (n (matrix-n-cols m1))) (loop :for i :from 0 :below m :do (loop :for j :from 0 :below n :do (setf (matrix-ref result i j) (- (matrix-ref result i j) (matrix-ref m2 i j))))) result))) (defgeneric matrix-elementwise-product (m1 m2 &key boolean) (:documentation "Return the result of multiplying the elements of matrix M1 and matrix M2. M1 and M2 must be the same size.")) (defmethod matrix-elementwise-product ((m1 matrix) (m2 matrix) &key boolean) (and (matrix-same-size-p m1 m2) (let ((result (matrix-copy m1)) (m (matrix-n-rows m1)) (n (matrix-n-cols m1))) (loop :for i :from 0 :below m :do (loop :for j :from 0 :below n :do (setf (matrix-ref result i j) (if boolean (if (* (matrix-ref result i j) (matrix-ref m2 i j)) 1 0) (* (matrix-ref result i j) (matrix-ref m2 i j)))))) result))) (defgeneric matrix-product (m1 m2) (:documentation "Return the result of multiplying matrix M1 and matrix M2. The number of columns of M1 must equal the number of rows of M2.")) (defmethod matrix-product ((m1 matrix) (m2 matrix)) (and (= (matrix-n-cols m1) (matrix-n-rows m2)) (loop :with m = (matrix-n-rows m1) :with n = (matrix-n-cols m1) :with l = (matrix-n-cols m2) :with c = (make-zeros-matrix (make-instance 'matrix) m l) :for i :below m :do (loop :for k :below l :do (setf (matrix-ref c i k) (loop :for j :below n :sum (* (matrix-ref m1 i j) (matrix-ref m2 j k))))) :finally (return c))) ) (defmethod matrix-product ((m1 fast-matrix) (m2 fast-matrix)) (and (= (matrix-n-cols m1) (matrix-n-rows m2)) (let ((result (make-instance 'fast-matrix))) (setf (self result) (fl.function::m* (self m1) (self m2))) result))) (defgeneric matrix-transpose (matrix) (:documentation "Return a new matrix that interchanges the rows and columns of MATRIX.")) (defmethod matrix-transpose ((matrix matrix)) (let ((m (matrix-n-rows matrix)) (n (matrix-n-cols matrix)) (result (make-instance 'matrix))) (setf result (make-zeros-matrix result n m)) (loop :for i :from 0 :below m :do (loop :for j :from 0 :below n :do (setf (matrix-ref result j i) (matrix-ref matrix i j)))) result)) (defmethod matrix-transpose ((fm fast-matrix)) (let ((result (make-instance 'fast-matrix))) (setf (self result) (fl.function::transpose (self fm))) result)) (defgeneric make-zeros-matrix (matrix rows cols) (:documentation "Return matrix MATRIX with ROWS rows and COLS columns of zeros.")) (defmethod make-zeros-matrix ((matrix matrix) rows cols) (setf (self matrix) (make-array (list rows cols) :element-type 'fixnum :initial-element 0)) matrix) (defmethod make-zeros-matrix ((fm fast-matrix) rows cols) (setf (self fm) (fl.function::zeros rows cols 'single-float)) fm) (defgeneric make-universal-matrix (matrix rows cols) (:documentation "Return a universal matrix with ROWS rows and COLS columns.")) (defmethod make-universal-matrix ((matrix matrix) rows cols) (setf (self matrix) (make-array (list rows cols) :element-type 'fixnum :initial-element 1)) matrix) (defmethod make-universal-matrix ((fm fast-matrix) rows cols) (setf (self fm) (fl.function::ones rows cols 'single-float)) fm) (defgeneric make-infinity-matrix (matrix rows cols) (:documentation "Return a matrix of ROWS rows and COLS cols with each entry set to infinity")) (defmethod make-infinity-matrix ((matrix matrix) rows cols) (progn (setf (self matrix) (make-array (list rows cols) :element-type 'fixnum :initial-element (infinite matrix))) matrix)) (defmethod make-infinity-matrix ((fm fast-matrix) rows cols) (progn (setf (self fm) (fl.function::zeros rows cols 'single-float)) (fl.function::fill! (self fm) (infinite fm)) ;; (loop :for i :from 0 :below rows :do ;; (loop :for j :from 0 :below cols :do ;; (setf (matrix-ref fm i j) infinity))) fm)) (defgeneric make-identity-matrix (matrix order) (:documentation "Return an identity matrix of order ORDER.")) (defmethod make-identity-matrix ((matrix matrix) order) (setf matrix (make-zeros-matrix matrix order order)) (loop :for i :from 0 :below order :do (setf (matrix-ref matrix i i) 1)) matrix) (defmethod make-identity-matrix ((fm fast-matrix) order) (setf (self fm) (fl.function::eye order order 'single-float)) fm) ;; Adapted from ;; https://rosettacode.org/wiki/Matrix-exponentiation_operator#Common_Lisp (defgeneric matrix-power (matrix exp) (:documentation "Raise MATRIX to the power EXP and return the result.")) (defmethod matrix-power ((matrix matrix) exp) (let ((m-rows (matrix-n-rows matrix))) (cond ((/= m-rows (matrix-n-cols matrix)) (error "Non-square matrix")) ((zerop exp) (make-identity-matrix matrix m-rows)) ((= 1 exp) (matrix-copy matrix)) ((zerop (mod exp 2)) (let ((me2 (matrix-power matrix (/ exp 2)))) (matrix-product me2 me2))) (t (let ((me2 (matrix-power matrix (/ (1- exp) 2)))) (matrix-product matrix (matrix-product me2 me2))))))) (defgeneric to-adjacency-matrix (graph matrix) (:documentation "Return the adjacency matrix of GRAPH.")) (defmethod to-adjacency-matrix ((graph graph) (matrix matrix)) (let ((node-index-hash (make-hash-table)) (counter -1)) (mapc (lambda (node) (setf (gethash node node-index-hash) (incf counter))) (nodes graph)) (setf matrix (make-zeros-matrix matrix (+ counter 1) (+ counter 1))) (mapc (lambda-bind ((a b)) (setf (matrix-ref matrix (gethash a node-index-hash) (gethash b node-index-hash)) 1) (setf (matrix-ref matrix (gethash b node-index-hash) (gethash a node-index-hash)) 1)) (edges graph)) matrix)) (defmethod to-adjacency-matrix ((graph digraph) (matrix matrix)) (let ((node-index-hash (make-hash-table)) (counter -1)) (mapc (lambda (node) (setf (gethash node node-index-hash) (incf counter))) (nodes graph)) (setf matrix (make-zeros-matrix matrix (+ counter 1) (+ counter 1))) (mapc (lambda-bind ((a b)) (setf (matrix-ref matrix (gethash a node-index-hash) (gethash b node-index-hash)) 1)) (edges graph)) matrix)) (defmethod to-adjacency-matrix ((graph graph) (matrix fast-matrix)) (let ((node-index-hash (make-hash-table)) (counter -1) (one 1.0s0)) (declare (type single-float one)) (mapc (lambda (node) (setf (gethash node node-index-hash) (incf counter))) (nodes graph)) (setf matrix (make-zeros-matrix matrix (+ counter 1) (+ counter 1))) (mapc (lambda-bind ((a b)) (setf (matrix-ref matrix (gethash a node-index-hash) (gethash b node-index-hash)) one) (setf (matrix-ref matrix (gethash b node-index-hash) (gethash a node-index-hash)) one)) (edges graph)) matrix)) (defmethod to-adjacency-matrix ((graph digraph) (matrix fast-matrix)) (let ((node-index-hash (make-hash-table)) (counter -1) (one 1.0s0)) (declare (type single-float one)) (mapc (lambda (node) (setf (gethash node node-index-hash) (incf counter))) (nodes graph)) (setf matrix (make-zeros-matrix matrix (+ counter 1) (+ counter 1))) (mapc (lambda-bind ((a b)) (setf (matrix-ref matrix (gethash a node-index-hash) (gethash b node-index-hash)) one)) (edges graph)) matrix)) (defgeneric to-reachability-matrix (graph matrix &key limit) (:documentation "Return the reachability matrix of the graph GRAPH. With the optional argument LIMIT set to an integer in the range 2 to two less than the number of nodes in GRAPH, produces a limited reachability matrix with paths of length LIMIT or less.")) (defmethod to-reachability-matrix ((graph graph) (matrix matrix) &key limit) (let ((n (length (nodes graph)))) (assert (or (not limit) (and (integerp limit) (> limit 1) (< limit (- n 1)))) (limit) "~S must be an integer between 2 and ~S" limit (- n 2)) (let* ((result (make-identity-matrix (make-instance 'matrix) n)) (max-power (or limit (- n 1))) (adjacency (to-adjacency-matrix graph (make-instance 'matrix))) (adjacency-powers (matrix-copy adjacency))) (setf result (matrix-sum adjacency result :boolean t)) (loop :for i :from 2 :to max-power :do (setf adjacency-powers (matrix-product adjacency-powers adjacency)) (setf result (matrix-sum adjacency-powers result :boolean t))) result))) (defmethod to-reachability-matrix ((graph graph) (matrix fast-matrix) &key limit) (let ((n (length (nodes graph)))) (assert (or (not limit) (and (integerp limit) (> limit 1) (< limit (- n 1)))) (limit) "~S must be an integer between 2 and ~S" limit (- n 2)) (let* ((result (make-identity-matrix (make-instance 'fast-matrix) n)) (max-power (or limit (- n 1))) (adjacency (to-adjacency-matrix graph (make-instance 'fast-matrix))) (adjacency-powers (matrix-copy adjacency))) (setf result (matrix-sum adjacency result :boolean t)) (loop :for i :from 2 :to max-power :do (setf adjacency-powers (matrix-product adjacency-powers adjacency)) (setf result (matrix-sum adjacency-powers result :boolean t))) result))) (defgeneric reachablep (graph rd from to) (:documentation "Given a graph GRAPH and a reachability matrix RD, returns t if node TO is reachable from node FROM, nil otherwise.")) (defmethod reachablep ((graph graph) (rd matrix) from to) (let ((node-index-hash (make-hash-table)) (counter -1)) (mapc (lambda (node) (setf (gethash node node-index-hash) (incf counter))) (nodes graph)) (= 1 (matrix-ref rd (gethash from node-index-hash) (gethash to node-index-hash))))) (defgeneric reachable-from (graph rd from) (:documentation "Given a reachability matrix RD, return a list of the nodes in graph GRAPH reachable from node FROM.")) (defmethod reachable-from ((graph graph) (rd matrix) from) (let ((node-index-hash (make-hash-table)) (counter -1) (result)) (mapc (lambda (node) (setf (gethash node node-index-hash) (incf counter))) (nodes graph)) (maphash #'(lambda (k v) (unless (= 0 (matrix-ref rd (gethash from node-index-hash) v)) (push k result))) node-index-hash) (reverse result))) (defgeneric to-strong-component-matrix (rd) (:documentation "Given a reachability matrix of a digraph, RD, return a matrix in which the strong component of GRAPH containing node_i is given by the entries of 1 in the ith row (or column).")) (defmethod to-strong-component-matrix ((rd matrix)) (matrix-elementwise-product rd (matrix-transpose rd))) (defgeneric strong-component-of (node graph strong-components) (:documentation "Return a list of nodes from graph GRAPH in the strong component that contains node NODE, as given by the strong component matrix STRONG-COMPONENTS.")) (defmethod strong-component-of (node (graph graph) (strong-components matrix)) (let ((node-index-hash (make-hash-table)) (counter -1) (result)) (mapc (lambda (node) (setf (gethash node node-index-hash) (incf counter))) (nodes graph)) (maphash #'(lambda (k v) (unless (= 0 (matrix-ref strong-components (gethash node node-index-hash) v)) (push k result))) node-index-hash) (reverse result))) (defgeneric to-distance-matrix (graph nd) (:documentation "Return the distance matrix ND of graph GRAPH.")) (defmethod to-distance-matrix ((graph graph) (nd matrix)) (let* ((a (to-adjacency-matrix graph (make-instance 'matrix))) (a-power (to-adjacency-matrix graph (make-instance 'matrix))) (m (matrix-n-rows a)) (finished) (zero 0) (one 1)) (declare (type fixnum one)) (declare (type fixnum zero)) (setf nd (make-infinity-matrix nd m m)) (loop :for i :from 0 :below m :do (setf (matrix-ref nd i i) zero)) (loop :for i :from 0 :below m :do (loop :for j :from 0 :below m :do (when (= (matrix-ref a i j) one) (setf (matrix-ref nd i j) one)))) (loop :for i :from 2 :to m :unless finished :do (setf a-power (matrix-product a a-power)) (setf finished t) (loop :for j :from 0 :below m :do (loop :for k :from 0 :below m :do (when (and (infinitep (matrix-ref nd j k) nd) (> (matrix-ref a-power j k) zero)) (setf (matrix-ref nd j k) (coerce i 'fixnum)) (setf finished nil))))) nd)) (defmethod to-distance-matrix ((graph graph) (nd fast-matrix)) (let* ((a (to-adjacency-matrix graph (make-instance 'fast-matrix))) (a-power (to-adjacency-matrix graph (make-instance 'fast-matrix))) (m (matrix-n-rows a)) (finished) (zero 0.0s0) (one 1.0s0)) (declare (type single-float one)) (declare (type single-float zero)) (setf nd (make-infinity-matrix nd m m)) (loop :for i :from 0 :below m :do (setf (matrix-ref nd i i) zero)) (loop :for i :from 0 :below m :do (loop :for j :from 0 :below m :do (when (= (matrix-ref a i j) one) (setf (matrix-ref nd i j) one)))) (loop :for i :from 2 :to m :unless finished :do (setf a-power (matrix-product a a-power)) (setf finished t) (loop :for j :from 0 :below m :do (loop :for k :from 0 :below m :do (when (and (infinitep (matrix-ref nd j k) nd) (> (matrix-ref a-power j k) zero)) (setf (matrix-ref nd j k) (coerce i 'single-float)) (setf finished nil))))) nd)) (defgeneric distance-from-to (graph nd from to) (:documentation "Returns the number of edges in graph GRAPH from node FROM to node TO, given the distance matrix ND.")) (defmethod distance-from-to ((graph graph) (nd matrix) from to) (let ((node-index-hash (make-hash-table)) (counter -1)) (mapc (lambda (node) (setf (gethash node node-index-hash) (incf counter))) (nodes graph)) (matrix-ref nd (gethash from node-index-hash) (gethash to node-index-hash)))) ;; Peirce's relational properties (defun reflexivep (graph matrix) :documentation "Returns t if GRAPH is reflexive, nil otherwise." (let ((a (to-adjacency-matrix graph matrix)) (result)) (loop :for j :from 0 :below (matrix-n-rows a) :unless result :do (setf result (not (= 1 (matrix-ref a j j))))) (not result))) (defun irreflexivep (graph matrix) :documentation "Returns t if GRAPH is irreflexive, nil otherwise." (let ((a (to-adjacency-matrix graph matrix)) (result)) (loop :for j :from 0 :below (matrix-n-rows a) :unless result :do (setf result (not (= 0 (matrix-ref a j j))))) (not result))) (defun symmetricp (graph matrix) :documentation "Returns t if GRAPH is symmetric, nil otherwise." (let* ((a (to-adjacency-matrix graph matrix)) (at (matrix-transpose a))) (if (matrix-entries-different-p a at) nil t))) (defun asymmetricp (graph matrix) :documentation "Returns t if GRAPH is asymmetric, nil otherwise." (let* ((a (to-adjacency-matrix graph matrix)) (at (matrix-transpose a)) (result)) (loop :for j :from 0 :below (matrix-n-rows a) :unless result :do (loop :for k :from 0 :below (matrix-n-rows a) :unless result :do (setf result (and (not (eq j k)) (eq (matrix-ref a j k) 1) (eq (matrix-ref at j k) 1))))) (not result))) (defun transitivep (graph matrix) :documentation "Returns t if GRAPH is transitive, nil otherwise." (let* ((a (to-adjacency-matrix graph matrix)) (a2 (matrix-product a a)) (two-path) (no-match)) (loop :for j :from 0 :below (matrix-n-rows a) :do (loop :for k :from 0 :below (matrix-n-rows a) :do (and (not two-path) (eq (matrix-ref a2 j k) 1) (setf two-path j)) (and (not no-match) (eq (matrix-ref a2 j k) 1) (eq (matrix-ref a j k) 0) (setf no-match j)))) (and two-path (not no-match)))) (defun intransitivep (graph matrix) :documentation "Returns t if GRAPH is intransitive, nil otherwise." (let* ((a (to-adjacency-matrix graph matrix)) (a2 (matrix-product a a)) (two-path) (match)) (loop :for j :from 0 :below (matrix-n-rows a) :do (loop :for k :from 0 :below (matrix-n-rows a) :do (and (not two-path) (eq (matrix-ref a2 j k) 1) (setf two-path j)) (and (not match) (not (eq j k)) (eq (matrix-ref a2 j k) 1) (eq (matrix-ref a j k) 1) (setf match j)))) (and two-path (not match)))) (defun completep (graph matrix) :documentation "Returns t if GRAPH is complete, nil otherwise." (let* ((a (to-adjacency-matrix graph matrix)) (at (matrix-transpose a)) (result)) (loop :for j :from 0 :below (matrix-n-rows a) :unless result :do (loop :for k :from 0 :below (matrix-n-rows a) :unless (or result (eq j k)) :do (setf result (and (eq (graph/matrix::matrix-ref a j k) 0) (eq (graph/matrix::matrix-ref at j k) 0))))) (not result))) (defun relational-structure (graph matrix) :documentation "Returns a string with the name of a relational structure whose axiom system GRAPH satisfies, or nil if no relational structure axiom system is satisfied." (let ((rnobar (reflexivep graph matrix)) (rbar (irreflexivep graph matrix)) (snobar (symmetricp graph matrix)) (sbar (asymmetricp graph matrix)) (tnobar (transitivep graph matrix)) (tbar (intransitivep graph matrix)) (cnobar (completep graph matrix))) (or (when (and rbar (not (or snobar sbar tnobar tbar cnobar))) "digraph") (when (and rbar snobar (not (or tnobar tbar cnobar))) "graph") (when (and rbar sbar (not (or tnobar tbar cnobar))) "oriented graph") (when (and rnobar snobar (not tnobar)) "similarity relation") (when (and rnobar snobar tnobar (not cnobar)) "equivalence relation") (when (and rbar sbar tnobar (not cnobar)) "partial order") (when (and rbar sbar tnobar cnobar) "complete order") (when (and rbar sbar cnobar (not (or tnobar tbar))) "tournament") (when (and rbar snobar tnobar (not cnobar)) "parity relation") (when (and rbar sbar tbar (not cnobar)) "antiequivalence relation") (when (and rnobar sbar tbar) "antiparity relation")))) graph-20180131-git/test.lisp000066400000000000000000000415151322077423300155160ustar00rootroot00000000000000;;; test/graph.lisp --- tests for the graph library ;; Copyright (C) Eric Schulte 2012 ;; Licensed under the Gnu Public License Version 3 or later ;;; Code: (defpackage #:graph/test (:use :common-lisp :alexandria :metabang-bind :graph :stefil :named-readtables :curry-compose-reader-macros) (:export :test)) (in-package :graph/test) (in-readtable :curry-compose-reader-macros) (defsuite test) (in-suite test) (defvar *graph* nil "Variable for use in graph tests.") (defvar *network* nil "Variable for use in graph tests.") (defvar *cycle* nil "Variable for use in graph tests.") (defvar *digraph* nil "Digraph for use in graph tests.") (defvar *halfs* nil "Variable for use in graph tests.") (defvar *star* nil "Variable for use in graph tests.") (defixture small-graph (:setup (setf *graph* (populate (make-instance 'graph) :nodes '(:foo :bar :baz :qux) :edges '((:foo :bar) (:foo :baz) (:bar :baz))))) (:teardown (setf *graph* nil))) (defixture less-small-graph (:setup (setf *graph* (populate (make-instance 'graph) :nodes '(:foo :bar :baz :qux :zap :zaf :fiz) :edges '((:foo :bar) (:bar :baz) (:baz :foo) (:zap :zaf) (:zaf :qux) (:qux :zap) (:fiz :fiz))))) (:teardown (setf *graph* nil))) (defixture normal-graph (:setup (setf *graph* (populate (make-instance 'graph) :nodes '(a b c d e f) :edges '((a b) (b c) (c d) (d e) (e c) (e f) (f b))))) (:teardown (setf *graph* nil))) (defixture small-network (:setup (setf *network* (populate (make-instance 'graph) :nodes '(:a :b :s :t) :edges-w-values '(((:a :b) . 1) ((:s :a) . 2) ((:s :b) . 1) ((:a :t) . 4) ((:b :t) . 2))))) (:teardown (setf *network* nil))) (defixture cycle (:setup (setf *cycle* (populate (make-instance 'digraph) :nodes '(:a :b :s :t) :edges-w-values '(((:s :a) . 1) ((:s :b) . 3) ((:b :a) . 1) ((:a :t) . 2) ((:b :t) . 2) ((:t :s) . 2))))) (:teardown (setf *cycle* nil))) (defixture digraph (:setup (setf *digraph* (populate (make-instance 'digraph) :nodes '(a b c d e f g) :edges-w-values '(((a b) . 3) ((b d) . 1) ((b c) . 2) ((c e) . 1) ((d e) . 2) ((e f) . 3)))))) (defixture halfs (:setup (setf *halfs* (populate (make-instance 'graph) :edges-w-values '(((:a :b) . 10) ((:b :c) . 10) ((:c :a) . 10) ((:q :r) . 20) ((:r :s) . 20) ((:s :q) . 20) ((:c :s) . 2))))) (:teardown (setf *halfs* nil))) (defixture star (:setup (setf *star* (populate (make-instance 'graph) :edges '((:a :s) (:b :s) (:c :s) (:d :s) (:e :s) (:f :s) (:g :s) (:h :s))))) (:teardown (setf *star* nil))) ;;; Tests (deftest make-graph-sets-nodes () (with-fixture small-graph (is (set-equal (nodes *graph*) '(:FOO :BAR :BAZ :QUX))))) (deftest make-graph-sets-edges () (with-fixture small-graph (is (set-equal (edges *graph*) '((:FOO :BAR) (:FOO :BAZ) (:BAR :BAZ)) :test 'tree-equal)))) (deftest node-edge-for-foo () (with-fixture small-graph (is (tree-equal (node-edges *graph* :foo) '((:FOO :BAZ) (:FOO :BAR)))) (is (tree-equal (setf (node-edges *graph* :foo) '((:foo :qux))) '((:FOO :BAZ) (:FOO :BAR)))) (is (tree-equal (node-edges *graph* :foo) '((:FOO :QUX)))) (is (set-equal (edges *graph*) '((:FOO :QUX) (:BAR :BAZ)) :test #'tree-equal)))) (deftest delete-an-edge-from-small-graph () (with-fixture small-graph (is (null (delete-edge *graph* '(:foo :bar)))) (is (= 2 (length (edges *graph*)))) (is (= 1 (length (node-edges *graph* :foo)))))) (deftest add-duplicate-edge-to-small-graph () (with-fixture small-graph (add-edge *graph* '(:bar :foo)) (is (not (member '(:bar :foo) (edges *graph*) :test #'tree-equal))) (is (not (member '(:bar :foo) (node-edges *graph* :bar)))))) (deftest edge-value-for-foo-bar () (with-fixture small-graph (is (null (edge-value *graph* '(:foo :bar)))) (setf (edge-value *graph* '(:foo :bar)) 22) (is (= 22 (edge-value *graph* '(:foo :bar)))))) (deftest copy-of-a-graph () (with-fixture small-graph (let ((c (copy *graph*))) (is (set-equal (nodes *graph*) (nodes c))) (is (set-equal (edges *graph*) (edges c) :test #'tree-equal)) (delete-node c :foo) (is (not (set-equal (nodes *graph*) (nodes c)))) (is (not (set-equal (edges *graph*) (edges c) :test #'tree-equal)))))) (deftest copy-of-a-graph-w-graph-equal () (with-fixture less-small-graph (is (graph-equal *graph* (copy *graph*))))) (deftest merge-nodes-in-small-graph () (with-fixture small-graph (setf *graph* (merge-nodes *graph* :bar :baz :new :zap)) (is (set-equal (nodes *graph*) '(:FOO :QUX :ZAP))) (is (set-equal (edges *graph*) '((:FOO :ZAP)) :test #'tree-equal)))) (deftest merge-nodes-in-small-network () (with-fixture small-network (setf *network* (merge-nodes *network* :a :b :new :ab)) (is (set-equal (nodes *network*) '(:S :T :AB))) (is (set-equal (edges-w-values *network*) '(((:S :AB) . 3) ((:AB :T) . 6)) :test #'tree-equal)))) (deftest merge-edges-in-small-graph () (with-fixture small-graph (merge-edges *graph* '(:foo :bar) '(:foo :baz)) (is (set-equal (edges *graph*) '((:BAR :BAZ) (:BAR :FOO :BAZ)) :test #'tree-equal)))) (deftest edge-neighbors-of-c-on-graph () (with-fixture less-small-graph (is (set-equal (edge-neighbors *graph* '(:foo :bar)) '((:BAZ :FOO) (:FOO :BAR) (:BAR :BAZ) (:FOO :BAR)) :test #'tree-equal)))) (deftest neighbors-of-c-on-graph () (with-fixture normal-graph (is (every (lambda (it) (member it (neighbors *graph* 'b))) '(a b c))))) (deftest neighbors-of-e-on-digraph () (with-fixture normal-graph (is (set-equal (neighbors (digraph-of *graph*) 'e) '(C F))))) (deftest conected-component-of-e-on-digraph () (with-fixture normal-graph (is (set-equal (connected-component (digraph-of *graph*) 'e) '(C E D B F))))) (deftest is-normal-digraph-connected () (with-fixture normal-graph (is (not (connectedp (digraph-of *graph*)))))) (deftest connected-component-e-in-normal-graph () (with-fixture normal-graph (is (set-equal (connected-component *graph* 'e) (nodes *graph*))))) (deftest connected-component-of-foo-in-small-digraph () (with-fixture small-graph (is (set-equal (connected-component (digraph-of *graph*) :foo) '(:foo :bar :baz))) (is (set-equal (connected-component (digraph-of *graph*) :bar) '(:bar :baz))))) (deftest connected-component-of-a-cycle () (with-fixture cycle (is (set-equal (connected-component *cycle* :s) (nodes *cycle*))))) (deftest connectedp-of-multiple-graphs () (with-fixture small-graph (is (not (connectedp *graph*)))) (with-fixture less-small-graph (is (not (connectedp *graph*)))) (with-fixture normal-graph (is (connectedp *graph*)))) (deftest connected-components-of-less-small-graph () (with-fixture less-small-graph (is (set-equal (connected-components *graph*) '((:ZAP :ZAF :QUX) (:FIZ) (:BAZ :FOO :BAR)) :test #'set-equal)))) (deftest strongly-connected-components-of-small-graph () (with-fixture small-graph (is (set-equal (strongly-connected-components *graph*) '((:QUX) (:BAR :BAZ :FOO)) :test #'set-equal)))) (deftest topological-sort-with-digraph () (with-fixture digraph (let ((s (topological-sort *digraph*))) (is (not (dolist (x (edges *digraph*)) (when (> (position (car x) s) (position (cadr x) s)) (return t)))))))) (deftest levels-with-digraph () (with-fixture digraph (let ((l (levels *digraph*))) (is (not (dolist (x (edges *digraph*)) (when (> (gethash (car x) l) (gethash (cadr x) l)) (return t)))))))) (deftest basic-cycles-of-small-graph () (with-fixture small-graph (is (set-equal (basic-cycles *graph*) '((:BAR :BAZ :FOO)) :test #'set-equal)))) (deftest basic-cycles-of-less-small-graph () (with-fixture less-small-graph (is (set-equal (basic-cycles *graph*) '((:ZAF :ZAP :QUX) (:BAR :BAZ :FOO)) :test #'set-equal)))) (deftest basic-cycles-of-graph () (with-fixture normal-graph (is (set-equal (basic-cycles *graph*) '((D C E) (D C B F E) (C B F E)) :test #'set-equal)))) (deftest cycles-of-graph () (with-fixture normal-graph (is (set-equal (cycles *graph*) '((D C E) (D C B F E) (C B F E)) :test #'set-equal)))) (deftest cycles-of-a-digraph () (with-fixture digraph (is (null (cycles *digraph*))))) (deftest minimum-spanning-tree-on-a-network () (with-fixture small-network (is (= (reduce #'+ (mapcar {edge-value *network*} (edges (minimum-spanning-tree *network*)))) 4)))) (deftest connected-groups-of-size-in-less-small-graph () (with-fixture less-small-graph (is (= (length (edges *graph*)) (length (connected-groups-of-size *graph* 2)))) (is (set-equal '((:foo :bar :baz) (:zaf :qux :zap)) (connected-groups-of-size *graph* 3) :test #'set-equal)) (is (null (connected-groups-of-size *graph* 4))))) (deftest closed-groups-in-less-small-graph () (with-fixture less-small-graph (is (every {closedp *graph*} (connected-groups-of-size *graph* 3))))) (deftest clustering-coefficient-of-less-small-graph () (with-fixture less-small-graph (is (= 1 (clustering-coefficient *graph*))))) (deftest cliques-of-some-graphs () (with-fixture less-small-graph (is (set-equal (cliques *graph*) '((:FIZ) (:QUX :ZAF :ZAP) (:FOO :BAZ :BAR)) :test #'set-equal))) (with-fixture halfs (is (set-equal (cliques *halfs*) '((:Q :S :R) (:C :S) (:A :C :B)) :test #'set-equal)))) (deftest shortest-path-between-foo-and-baz-or-qux () (with-fixture less-small-graph (is (tree-equal (shortest-path (digraph-of *graph*) :foo :baz) '((:FOO :BAR) (:BAR :BAZ)))))) (deftest shortest-path-through-a-residual () (with-fixture cycle (let* ((flow '(((:A :T) . 1) ((:S :A) . 1) ((:B :T) . 2) ((:S :B) . 2))) (residual (residual *cycle* flow))) (is (shortest-path residual :s :t))))) (deftest shortest-path-against-undirected-edge () (with-fixture star (is (tree-equal (shortest-path *star* :a :g) '((:a :s) (:g :s)))))) (deftest residual-of-a-small-network () (with-fixture small-network (let ((orig-edges (copy-tree (edges-w-values *network*))) (resi-edges (edges-w-values (residual (digraph-of *network*) '(((:s :a) . 2) ((:a :t) . 2)))))) (is (= (cdr (assoc '(:a :s) resi-edges :test 'tree-equal))) 2) (is (= (cdr (assoc '(:a :t) resi-edges :test 'tree-equal))) 2) (is (tree-equal orig-edges (edges-w-values *network*)))))) (deftest max-flow-on-a-small-network () (with-fixture small-network (multiple-value-bind (path flow) (max-flow (digraph-of *network*) :s :t) (is (set-equal path '(((:A :T) . 2) ((:S :A) . 2) ((:B :T) . 1) ((:S :B) . 1)) :test #'tree-equal)) (is (= flow 3))))) (deftest max-flow-with-a-cycle () (with-fixture cycle (multiple-value-bind (flow value) (max-flow *cycle* :s :t) (is (set-equal flow '(((:B :A) . 1) ((:A :T) . 2) ((:S :A) . 1) ((:B :T) . 2) ((:S :B) . 3)) :test #'tree-equal)) (is (= value 4))))) (deftest min-cut-on-a-small-network () (with-fixture small-network (multiple-value-bind (cut weight) (min-cut *network*) (is (set-equal cut '((:S) (:T :B :A)) :test 'set-equal)) (is (= 3 weight))))) (deftest min-cut-on-a-graph-of-two-halfs () (with-fixture halfs (multiple-value-bind (cut weight) (min-cut *halfs*) (is (set-equal cut '((:a :b :c) (:q :r :s)) :test 'set-equal)) (is (= 2 weight))))) (deftest small-graph-to-plist () (with-fixture small-graph (let* ((plist (to-plist *graph*)) (edges (mapcar {mapcar {position _ (mapcar #'second (getf plist :nodes))}} (edges *graph*)))) (is (set-equal (getf plist :nodes) '((:NAME :FOO) (:NAME :BAR) (:NAME :BAZ) (:NAME :QUX)) :test 'tree-equal)) (is (set-equal (mapcar {getf _ :edge} (getf plist :edges)) edges :test 'set-equal)) (is (set-equal (mapcar {getf _ :value} (getf plist :edges)) '(NIL NIL NIL NIL)))))) (deftest two-way-plist-conversion-on-multiple-graphs () (with-fixture small-graph (is (graph-equal *graph* (from-plist (make-instance 'graph) (to-plist *graph*))))) (with-fixture less-small-graph (is (graph-equal *graph* (from-plist (make-instance 'graph) (to-plist *graph*))))) (with-fixture small-network (is (graph-equal *network* (from-plist (make-instance 'graph) (to-plist *network*)))))) (deftest test-preferential-attachment-population () (let ((graph (make-instance 'graph)) (many 1000)) (preferential-attachment-populate graph (loop :for i :below many :collect i)) (is (= many (length (nodes graph)))) (is (= (1- many) (length (edges graph)))))) (deftest test-erdos-renyi-graphs () (let ((g (erdos-renyi-graph 8 16))) (is (= 8 (length (nodes g)))) (is (= 16 (length (edges g))))) (let ((dg (erdos-renyi-digraph 3 5))) (is (= 3 (length (nodes dg)))) (is (= 5 (length (edges dg)))))) (deftest farness-of-s-in-network () (with-fixture small-network (is (= 4 (farness *network* :s))))) (deftest betweenness-of-center-of-a-star () (with-fixture star (is (= 1 (betweenness *star* :s))) (is (= 0 (betweenness *star* :a))))) (deftest conversion-to-value-matrix () (flet ((sum (array) (let ((dims (array-dimensions array))) (reduce #'+ (mapcar {reduce #'+} (loop :for x :below (first dims) :collect (loop :for y :below (second dims) :collect (let ((val (aref array x y))) (cond ((numberp val) val) ((null val) 0) (t 1)))))))))) (with-fixture small-network (is (= (sum (to-value-matrix *network*)) (reduce #'+ (mapcar #'cdr (edges-w-values *network*)))))) (with-fixture halfs (is (= (sum (to-value-matrix *halfs*)) (reduce #'+ (mapcar #'cdr (edges-w-values *halfs*)))))))) (deftest conversion-from-value-matrix () (is (set-equal (edges-w-values (from-value-matrix (make-instance 'graph) #2A((nil 1 nil) (nil nil 2) (nil nil nil)))) '(((1 2) . 2) ((0 1) . 1)) :test 'equalp)))