add helper function to return region predictions

add a helper function to return the set of column predictions in the
region (ANSI C HTM)

Author: binarybarry

src/HTM/c_ansi/Region.c

@@ -414,6 +414,42 @@ void deleteRegion(Region* region) {
   region->inputCells = NULL;
 }
 
+/**
+ * Populate the outData array with the current prediction values for each
+ * column in the Region.  The array must be have a size equal to the number of
+ * columns in the Region (region->numCols). The value returned for a column
+ * represents the fewest number of time steps the column believes an activation
+ * will occur. For example a 1 value means the column is predicting it will
+ * become active in the very next time step (t+1).  A value of 2 means it expects
+ * activation in 2 time steps (t+2) etc.  A value of 0 means the column is not
+ * currently making any prediction.
+ * @param outData this array will be populated with the prediction values for
+ * each column in the region based on the most recently processed time step.
+ * This array must be have length equal to the number of columns in the
+ * region.
+ */
+void getColumnPredictions(Region* region, char* outData) {
+  int i,j;
+  for(i=0; i<region->numCols; ++i) {
+    Column* col = &(region->columns[i]);
+    outData[i] = 0;
+
+    /*if a column has multiple predicting cells, find the one that is making
+      the prediction that will happen the earliest and store that value*/
+    bool colOK = false;
+    char p = MAX_TIME_STEPS;
+    for(j=0; j<col->numCells; ++j) {
+      Cell* cell = &(col->cells[j]);
+      if(cell->isPredicting && cell->predictionSteps < p) {
+        p = cell->predictionSteps;
+        colOK = true;
+      }
+    }
+    if(colOK)
+      outData[(col->cy*region->width)+col->cx] = p;
+  }
+}
+
 /**
  * Calculate both the activation accuracy and the prediction accuracy for all
  * the column cells in this region within the last processed time step.

src/HTM/c_ansi/Region.h

@@ -52,6 +52,7 @@ Region* newRegion(int inputSizeX, int inputSizeY, int colGridSizeX, int colGridS
     float pctLocalActivity, int cellsPerCol, int segActiveThreshold,
     int newSynapseCount, char* inputData);
 void deleteRegion(Region* region);
+void getColumnPredictions(Region* region, char* outData);
 void getLastAccuracy(Region* region, float* result);
 int numRegionSegments(Region* region, int predictionSteps);
 int numRegionActiveColumns(Region* region);

src/HTM/c_ansi/UnitTests.c

@@ -284,6 +284,7 @@ void testRegion1() {
 
   deleteRegion(region);
   free(region);
+  free(data);
 
   printf("OK\n");
 }
@@ -332,6 +333,7 @@ void testRegion2() {
 
   deleteRegion(region);
   free(region);
+  free(data);
 
   printf("OK\n");
 }
@@ -365,6 +367,8 @@ void testRegion3() {
   int segActiveThreshold = 10;
   int newSynapseCount = 10;
 
+  char* outData = malloc(colGridSizeX * colGridSizeY);
+
   Region* region = newRegion(inputSizeX, inputSizeY, colGridSizeX, colGridSizeY,
         pctInputPerCol, pctMinOverlap, localityRadius, pctLocalActivity, cellsPerCol,
         segActiveThreshold, newSynapseCount, data);
@@ -388,6 +392,21 @@ void testRegion3() {
       int nc = numRegionActiveColumns(region);
       if(DEBUG)
         printf(" nc:%d", nc);
+
+      /*Get the current column predictions.  outData is size 32x32 to match the
+       * column grid.  each value represents whether the column is predicted to
+       * happen soon.  a value of 1 indicates the column is predicted to be active
+       * in t+1, value of 2 for t+2, etc.  value of 0 indicates column is not
+       * being predicted any time soon. */
+      getColumnPredictions(region, outData);
+      int p,n1=0, n2=0, n3=0;
+      for(p=0; p<region->numCols; ++p) {
+        n1 += outData[p]==1 ? 1 : 0;
+        n2 += outData[p]==2 ? 1 : 0;
+        n3 += outData[p]==3 ? 1 : 0;
+      }
+      if(DEBUG)
+        printf(" np:%i %i %i", n1, n2, n3);
     }
     if(DEBUG)
       printf("\n");
@@ -397,6 +416,8 @@ void testRegion3() {
 
   deleteRegion(region);
   free(region);
+  free(data);
+  free(outData);
 
   printf("OK\n");
 }
@@ -539,6 +560,7 @@ void testRegionPerformance(unsigned int nunique) {
 
   deleteRegion(region);
   free(region);
+  free(data);
 
   printf("OK\n");
 }
@@ -677,6 +699,7 @@ void testRegionPerformanceDickens() {
 
   deleteRegion(region);
   free(region);
+  free(data);
 
   printf("OK\n");
 }