Cut out piece of matrix based upon other matrix

Hi,

I have a DEM of an area represented by an array 46592x3 (first colom: X-coordinate, second colom: Y-coordinate, third colom: elevation). Next to that, I have a 11155x3 matrix (first colom: X-coordinate, second colom: Y-coordinate, third colom: 0 of no glacier present and 1 if glacier present). The extent of the second matrix lays completely within the first matrix.

I now want to cut out that part of the DEM (first array) where only the glacier is present (value 1 in the second array).

Can someone help me?

Thanks!

Answer 1

[Jan]

glacierPos = B(B(:, 3) == 1, 1:2);  % Coordinates of glacier
inGlacier  = ismember(DEM(:, 1:2), glacierPos, 'rows');
Wanted     = DEM(inGlacier, :);