I would use:
dm = diff(M,[],dim);
dmean = mean(dm);
dstd = std(dm);
where ‘M’ is your matrix, to initially assess them.
For evenly-spaced elements,‘dstd’ should be on hte order of 1E-15 or less, although that has to be taken in the context of the value of ‘dmean’, which is the reason for calculating it. If you want to be certain the elements are evenly-spaced in the appropriate dimension, use the Signal Processing Toolbox resample function to resample them to a constant sampling interval.
