I have had my fair share of times when I got weird results form using interp1. Usually I'd find a hidding NaN somewhere or maybe some weird spline behavior. This time I'm stumped. my source data is clean, no NaNs in my underlying values or desired extrapolated values. I' not extrapolating even. I tried several methods and keep getting weird results. Should be an easy one! I'm getting Nan's up to 20 Hz (b and c are Hz in my case). The rest of the test variable is mostly NaNs with a few non NaN numbers which seem to have little relation to the source data. I can't understand this!
test = interp1(a,b,c);