public Vector columnSums() throws MatricksException {
Vector sums = new DenseDoubleVector(numCols());
MatrixCursor cursor = cursor();
while (cursor.next()) {
sums.set(cursor.col(), cursor.val() + sums.get(cursor.col()));
}
return sums;
}
public Vector rowSums() throws MatricksException {
// TODO: can change this to a lower level interface,
// taking in an array of doubles and not allocating ... ?
Vector sums = new DenseDoubleVector(numRows());
// TODO: optimize out row() with local var? microopt, measure speed
MatrixCursor cursor = cursor();
while (cursor.next()) {
sums.set(cursor.row(), cursor.val() + sums.get(cursor.row()));
}
return sums;
}
