Functions which Return Indices of a Region

Is there a function in MATLAB that takes as input: a matrix, 'X', an index, 'Y', and a scale 'S', and returns a matrix of indices, 'D', corresponding to a square in 'X', with center 'Y', and length equivalent to twice the scale, 'S'?

EDIT: Added the figure for illustration

[Azzi Abdelmalek]

can you explain with an example?

[Pyroholic]

Hello, Azzi. Did you see the illustration I just added? If so, do you still want an example?

Answer 1

[Guillaume]

There are many way to do this. One of them:

allindices = reshape(1:numel(X), size(X));
[centrerow, centrecol] = ind2sub(size(X), Y);
halfscale = floor(S / 2);
D = allindices(max(1, centrerow - halfscale) : min(size(X, 1), centrerow + halfscale), ...
               max(1, centrecol - halfscale) : min(size(X, 2), centrecol + halfscale))

[Guillaume]

And another way:

halfscale = floor(S / 2);
D = bsxfun(@plus, (-halfscale:halfscale)', (-halfscale:halfscale)*size(X, 1) + Y)

This needs cropping if Y is near the edges, though.

[Pyroholic]

Thank you, Guilaume for helping me out. I highly recommend the answer in the first comment. The one in the second comment gave me wrong results. Thanks again.

[Guillaume]

There was an extra bracket in the second answer which I have now removed. Both answers should give the exact same result for Y that's not near the edges.