Max change in z within a certain radius of a point

I’m relatively new to MATLAB and looking for some help. I have three equal sized matrices that define x, y and z. The matrices represents mapping data where x is an easting, y is a northing, and z is an elevation. x and y are set up on a regular grid (say, both 0:5:500), z is a variable (for example, survey data). For each grid point (x,y) I want to check the maximum difference in z within a given radius. Ultimately, the goal is to ascertain if there is an elevation change greater than say 6” within 20-ft.

Answer 1

[darova]

Use logical conditions

ix = (x-x0).^2 + (y-y0).^2 < 20^2;
z(ix)    % all z values around (x0,y0) r=20