/**
* Updates the minimum duty cycles in a global fashion. Sets the minimum duty cycles for the
* overlap and activation of all columns to be a percent of the maximum in the region, specified
* by {@link Connections#getMinOverlapDutyCycles()} and minPctActiveDutyCycle respectively.
* Functionality it is equivalent to {@link #updateMinDutyCyclesLocal(Connections)}, but this
* function exploits the globalness of the computation to perform it in a straightforward, and
* more efficient manner.
*
* @param c
*/
public void updateMinDutyCyclesGlobal(Connections c) {
Arrays.fill(
c.getMinOverlapDutyCycles(),
c.getMinPctOverlapDutyCycles() * ArrayUtils.max(c.getOverlapDutyCycles()));
Arrays.fill(
c.getMinActiveDutyCycles(),
c.getMinPctActiveDutyCycles() * ArrayUtils.max(c.getActiveDutyCycles()));
}
/**
* Updates the minimum duty cycles. The minimum duty cycles are determined locally. Each column's
* minimum duty cycles are set to be a percent of the maximum duty cycles in the column's
* neighborhood. Unlike {@link #updateMinDutyCyclesGlobal(Connections)}, here the values can be
* quite different for different columns.
*
* @param c
*/
public void updateMinDutyCyclesLocal(Connections c) {
int len = c.getNumColumns();
for (int i = 0; i < len; i++) {
int[] maskNeighbors =
getNeighborsND(c, i, c.getMemory(), c.getInhibitionRadius(), true).toArray();
c.getMinOverlapDutyCycles()[i] =
ArrayUtils.max(ArrayUtils.sub(c.getOverlapDutyCycles(), maskNeighbors))
* c.getMinPctOverlapDutyCycles();
c.getMinActiveDutyCycles()[i] =
ArrayUtils.max(ArrayUtils.sub(c.getActiveDutyCycles(), maskNeighbors))
* c.getMinPctActiveDutyCycles();
}
}
/**
* Updates the duty cycles for each column. The OVERLAP duty cycle is a moving average of the
* number of inputs which overlapped with each column. The ACTIVITY duty cycles is a moving
* average of the frequency of activation for each column.
*
* @param c the {@link Connections} (spatial pooler memory)
* @param overlaps an array containing the overlap score for each column. The overlap score for a
* column is defined as the number of synapses in a "connected state" (connected synapses)
* that are connected to input bits which are turned on.
* @param activeColumns An array containing the indices of the active columns, the sparse set of
* columns which survived inhibition
*/
public void updateDutyCycles(Connections c, int[] overlaps, int[] activeColumns) {
double[] overlapArray = new double[c.getNumColumns()];
double[] activeArray = new double[c.getNumColumns()];
ArrayUtils.greaterThanXThanSetToYInB(overlaps, overlapArray, 0, 1);
if (activeColumns.length > 0) {
ArrayUtils.setIndexesTo(activeArray, activeColumns, 1);
}
int period = c.getDutyCyclePeriod();
if (period > c.getIterationNum()) {
period = c.getIterationNum();
}
c.setOverlapDutyCycles(
updateDutyCyclesHelper(c, c.getOverlapDutyCycles(), overlapArray, period));
c.setActiveDutyCycles(updateDutyCyclesHelper(c, c.getActiveDutyCycles(), activeArray, period));
}