MATLAB: Resample matrix by distance

Question

I need to resample a matrix [x,y,z,rad,dist] by the distance. This is a non constant frequency.

I want a frequency of 0,1 mm per sample. For now i have a distance of 162,2 mm over 118 samples, but this can vary by every single file.

I want an automatic file which resamples the matrix to a sample frequency of 0.1 mm per sample.

Can I maybe make a for loop with the resample method? And how should it look like?

Answer 1

Since you have approximately 1.5 mm between samples on average you will have to do some re-interpolation of your data. This works provided the assumption that the interpolation-scheme is reasonable for your data. That is up for you to check/verify/demonstrate/argue/show/assume. This can be done something like this:

sample_dist = your_data(:,5);
dist_interp = min(sample_dist):0.1:max(sample_dist);
if dist_interp(end) < max(sample_dist)
  dist_interp(end+1) = max(sample_dist);
end
data_reinterp = interp1(sample_dist,your_data,dist_interp,'pchip');

This works provided dist varies monotonically.

HTH