Type build-syntactic-interaction-graph.

networks.rkt

@@ -23,7 +23,7 @@
    network-form->network/01 make-boolean-network-form
    forms->boolean-network
 
-   list-syntactic-interactions
+   list-syntactic-interactions build-syntactic-interaction-graph
    )
 
   (define-type (State a) (VariableMapping a))
@@ -254,6 +254,27 @@
                                                  (b . (- b c)))))
       (check-true (set=? (list-syntactic-interactions n 'a) '(a b)))
       (check-true (set=? (list-syntactic-interactions n 'b) '(b)))))
+
+  (: build-syntactic-interaction-graph (All (a) (-> (NetworkForm a) Graph)))
+  (define (build-syntactic-interaction-graph n)
+    (transpose
+     (unweighted-graph/adj
+      (for/list ([(var _) (in-hash (network-form-forms n))])
+        (cons var (list-syntactic-interactions n var))))))
+
+  (module+ test
+    (test-case "build-syntactic-interaction-graph"
+      (define n (make-boolean-network-form #hash((a . (+ a b c))
+                                                 (b . (- b c)))))
+      (define ig (build-syntactic-interaction-graph n))
+      (check-true (has-vertex? ig 'a))
+      (check-true (has-vertex? ig 'b))
+      (check-false (has-vertex? ig 'c))
+      (check-true (has-edge? ig 'a 'a))
+      (check-true (has-edge? ig 'b 'a))
+      (check-true (has-edge? ig 'b 'b))
+      (check-false (has-edge? ig 'c 'b))
+      (check-false (has-edge? ig 'c 'a))))
   )
 
 (require 'typed)
@@ -270,8 +291,7 @@
                [struct dynamics ([network network?]
                                  [mode mode?])])
  ;; Functions
- (contract-out [build-syntactic-interaction-graph (-> network-form? graph?)]
+ (contract-out [interaction? (-> network? variable? variable? boolean?)]
-               [interaction? (-> network? variable? variable? boolean?)]
                [get-interaction-sign (-> network? variable? variable? (or/c #f -1 0 1))]
                [build-interaction-graph (-> network? graph?)]
                [build-interaction-graph/form (-> network-form? graph?)]
@@ -420,41 +440,6 @@
 ;;; Inferring interaction graphs
 ;;; ============================
 
-
-
-;;; Builds the graph in which the vertices are the variables of a
-;;; given network, and which contains an arrow from a to b whenever a
-;;; appears in (list-interactions a).
-;;;
-;;; Note that, while this definition is an easy one to check
-;;; structurally, this is *not* how interaction graphs are typically
-;;; defined.  An interaction graph is usually defined based on the
-;;; dynamics of the network: an arrow from a variable x to a variable
-;;; y means that varying x and only x may have an influence on the
-;;; value of y.  It is easy to imagine a situation in which the
-;;; syntactic interaction graph does not in fact agree with this
-;;; criterion, the simplest example being the network y = x AND (NOT
-;;; x).
-(define (build-syntactic-interaction-graph n)
-  (transpose
-   (unweighted-graph/adj
-    (for/list ([(var _) (in-hash (network-form-forms n))])
-      (cons var (list-syntactic-interactions n var))))))
-
-(module+ test
-  (test-case "build-syntactic-interaction-graph"
-    (define n (make-boolean-network-form #hash((a . (+ a b c))
-                                               (b . (- b c)))))
-    (define ig (build-syntactic-interaction-graph n))
-    (check-true (has-vertex? ig 'a))
-    (check-true (has-vertex? ig 'b))
-    (check-false (has-vertex? ig 'c))
-    (check-true (has-edge? ig 'a 'a))
-    (check-true (has-edge? ig 'b 'a))
-    (check-true (has-edge? ig 'b 'b))
-    (check-false (has-edge? ig 'c 'b))
-    (check-false (has-edge? ig 'c 'a))))
-
 ;;; Given a hash-set mapping variables to generic sets of their
 ;;; possible values, constructs the list of all possible states.
 (define (build-all-states vars-domains)

scribblings/networks.scrbl

@@ -366,6 +366,19 @@ The variables which are not part of the network are excluded from the listing.
  'a)
 ]}
 
+@defproc[(build-syntactic-interaction-graph [n (NetworkForm a)])
+					    Graph]{
+
+Builds the graph in which the vertices are the variables of a given network,
+and which contains an arrow from @racket[x] to @racket[y] whenever @racket[x]
+appears in @racket[(list-interactions y)].
+
+@ex[
+(require (only-in "utils.rkt" dotit))
+(dotit (build-syntactic-interaction-graph
+        (make-boolean-network-form #hash((a . (+ a b))
+                                         (b . (- b))))))
+]}
 
 @section{Dynamics of networks}