I have a binary rectangular T/F matrix; I need to be able to calculate the shortest path (i.e., Pythagorean distance) between a populated cell in row j and any populated cell in some row j+n. For instance, if I have a chessboard with random black/white square colors, I need the shortest distance (linear distance, not number of steps) for a king to get from a specified black space on the first row, to _any_ black space in a specified further row, traveling only on black spaces. Any idea? Thanks, -bryan [[alternative HTML version deleted]]