MATLAB: Correlation between two differently sized data sets

Question

Assume that I have solved a System with an ODE-Solver. The results [T1,Y1] (time and corresponding solution vector) I obtained for specific tolerances.

Now I have changed the tolerances and have [T2,Y2]. Although the time span for simulation remains the same these data sets have different lengths.

For example these lengths:

T1: 200×1, Y1: 200×3

T2: 500×1, Y2: 500×3

Now i can plot these sets easily for each component of Y into one plot, so I can see the differences. What I would like to do now is calculate the correlation coefficient to see how well these data sets match. My problem is this:

I can only correlate them, if the vectors of Y have the same length. So how do I expand the vector Y1 to match the size of Y2, obviously while keeping the same relation to the times T1 and T2 (which should then actually be the same)?

I tried interp() and resample(), but that does not work for me…

Answer 1

NewY2 = interp1(T2,Y2,T1);