/**
* find all columns from allColumns within inhibitionRadius of column col excluding the col itself
*
* @param col
* @param allColumns
* @param inhibitionRadius
* @return
*/
private static List<Column> findMyNeigbors(
Column col, Column[][] allColumns, double inhibitionRadius) {
List<Column> neighbors = new ArrayList<>();
int inhib = (int) Math.round(inhibitionRadius);
Point pos = SpatialPooler.getColumnPosition(col, allColumns);
int xxStart = HelperMath.inRange(pos.x - inhib, 0, allColumns.length);
int xxEnd = HelperMath.inRange(pos.x + inhib + 1, 0, allColumns.length);
int yyStart = HelperMath.inRange(pos.y - inhib, 0, allColumns[0].length);
int yyEnd = HelperMath.inRange(pos.y + inhib + 1, 0, allColumns[0].length);
for (int y = yyStart; y < yyEnd; y++) {
for (int x = xxStart; x < xxEnd; x++) {
if (y == pos.y && x == pos.x) {
continue; // skip myself
}
neighbors.add(allColumns[x][y]);
}
}
return neighbors;
}
/**
* Phase 2: Inhibition The second phase calculates which columns remain as winners after the
* inhibition step. desiredLocalActivity is a parameter that controls the number of columns that
* end up winning. For example, if desiredLocalActivity is 10, a column will be a winner if its
* overlap score is greater than the score of the 10'th highest column within its inhibition
* radius.
*/
public void computeWinningColumsAfterInhibition() {
activeColumns = new ArrayList<>();
for (int x = 0; x < xxMax; x++) {
for (int y = 0; y < yyMax; y++) {
if (Math.round(this.inhibitionRadius) != Math.round(this.inhibitionRadiusBefore)
|| columns[x][y].getNeigbours() == null) {
columns[x][y].setNeigbours(
SpatialPooler.findMyNeigbors(columns[x][y], this.columns, inhibitionRadius));
}
double minimalLocalActivity = kthScore(columns[x][y].getNeigbours(), desiredLocalActivity);
// TODO if inhibitionRadius changes, shouldn't this also change?
columns[x][y].setMinimalLocalActivity(minimalLocalActivity);
if (columns[x][y].getOverlap() >= minimalLocalActivity) {
columns[x][y].setActive(true);
activeColumns.add(columns[x][y]);
} else {
columns[x][y].setActive(false);
}
}
}
}