Index exceeds array bounds from CorrCoeff

I am trying to calculate cumulative correlation coefficient matrix from 2 different arrays saved in matrix X

Now I only need to save the correlation coefficient in position (1,2) as corrcoeff typically gives 2x2 elements. However, I got this error code: Index in position 2 exceeds array bounds (must not exceed 1).

What's wrong with code below?

for b = 1:1000

corr_coeff = corrcoef(X(1:b,1),X(1:b,2)) % Calculate the cumulative corr.coeff between X(1:b) of column 1 and X(1:b) of column 2

CC(b,:) = [b corr_coeff(1,2)];

end

When I do not give the command CC(b,:) = [b corr_coeff(1,2)]; I don't have any problem?

Answer 1

[the cyclist]

The problem is that in the first iteration of your loop, you are taking the correlation of two scalar values:

corrcoef(X(1,1),X(1,2))

which will just give the value 1, not a 2x2 matrix.

Maybe start your loop from b=2?

[cniv_we]

Ah alright, that works. Thank you.