Add options to propagate()

{ decay: 40, memoryPerf: 100} by default

Author: parmentf

lib/concept-network-state.js

@@ -171,8 +171,13 @@ ConceptNetworkState.prototype = {
    * ### propagate
    *
    * Propagate the activation values along the links.
+   *
+   * @param {Object} options {decay,memoryPerf}
    **/
-  propagate : function () {
+  propagate : function (options) {
+    if (options && typeof options !== 'object') {
+      throw new Error("propagate() parameter should be an object");
+    }
     var influenceNb = [];    // nodeId -> nb of influence number
     var influenceValue = []; // nodeId -> influence value
     for (var nodeId in this.nodeState) {
@@ -211,8 +216,14 @@ ConceptNetworkState.prototype = {
       if (typeof nodeState === 'undefined') {
         nodeState = { activationValue: 0, oldActivationValue: 0, age: 0 };
       }
-      var decay = 40;
-      var memoryPerf = 100;
+      if (!options) {
+        options = {
+          decay      : 40,
+          memoryPerf : 100
+        };
+      }
+      var decay      = options.decay || 40;
+      var memoryPerf = options.memoryPerf || 100;
       var minusAge = 200 / (1 + Math.exp(-nodeState.age / memoryPerf)) - 100;
       var newActivationValue;
       // If this node is not influenced at all

test/concept-network-state_test.js

@@ -235,6 +235,26 @@ describe('ConceptNetworkState', function () {
       assert.equal(cns.getActivationValue(node2.id) > 0, true);
     });
 
+    it('should accept options', function () {
+      assert.doesNotThrow(function () {
+        cns.propagate({anything: 1});
+      },
+      null,
+      "unexpected error");
+    });
+
+    it('should take decay into account', function () {
+      cns.propagate({decay: 200});
+      assert.deepEqual(cns.nodeState, {}, 'all nodes should be deactivated');
+    });
+
+    it('should take memoryPerf into account', function () {
+      cns.activate(node1.id);
+      cns.propagate({memoryPerf: Infinity});
+      assert.equal(cns.getActivationValue(node1.id), 60,
+        'with an infinite memory perf, activation should not decay too much');
+    });
+
   });
 
 });