/**
* This is the primary public method of the SpatialPooler class. This function takes a input
* vector and outputs the indices of the active columns. If 'learn' is set to True, this method
* also updates the permanences of the columns.
*
* @param inputVector An array of 0's and 1's that comprises the input to the spatial pooler. The
* array will be treated as a one dimensional array, therefore the dimensions of the array do
* not have to match the exact dimensions specified in the class constructor. In fact, even a
* list would suffice. The number of input bits in the vector must, however, match the number
* of bits specified by the call to the constructor. Therefore there must be a '0' or '1' in
* the array for every input bit.
* @param activeArray An array whose size is equal to the number of columns. Before the function
* returns this array will be populated with 1's at the indices of the active columns, and 0's
* everywhere else.
* @param learn A boolean value indicating whether learning should be performed. Learning entails
* updating the permanence values of the synapses, and hence modifying the 'state' of the
* model. Setting learning to 'off' freezes the SP and has many uses. For example, you might
* want to feed in various inputs and examine the resulting SDR's.
*/
public void compute(Connections c, int[] inputVector, int[] activeArray, boolean learn) {
if (inputVector.length != c.getNumInputs()) {
throw new InvalidSPParamValueException(
"Input array must be same size as the defined number of inputs: From Params: "
+ c.getNumInputs()
+ ", From Input Vector: "
+ inputVector.length);
}
updateBookeepingVars(c, learn);
int[] overlaps = c.setOverlaps(calculateOverlap(c, inputVector));
double[] boostedOverlaps;
if (learn) {
boostedOverlaps = ArrayUtils.multiply(c.getBoostFactors(), overlaps);
} else {
boostedOverlaps = ArrayUtils.toDoubleArray(overlaps);
}
int[] activeColumns = inhibitColumns(c, c.setBoostedOverlaps(boostedOverlaps));
if (learn) {
adaptSynapses(c, inputVector, activeColumns);
updateDutyCycles(c, overlaps, activeColumns);
bumpUpWeakColumns(c);
updateBoostFactors(c);
if (isUpdateRound(c)) {
updateInhibitionRadius(c);
updateMinDutyCycles(c);
}
}
Arrays.fill(activeArray, 0);
if (activeColumns.length > 0) {
ArrayUtils.setIndexesTo(activeArray, activeColumns, 1);
}
}
