How to find correlation coefficient between measured data and mathematically retrieved data without corr2.

I dont have image processing toolbox with my license. I m interested to find correlation coeff between two matrices.

Answer 1

[ANKUR KUMAR]

First method: Use corrcoef to find the correlation coefficient which yields a 2*2 matrix. eg.

   A=corrcoef(randi(35,9,9),randi(25,9,9));

result is A=

    1.0000    0.0441
    0.0441    1.0000

So, you can use A(1,2) or A(2,1).

Second method: If you find the correlation, then you can use corr2(A,B), where A and B must be of equal dimension. It gives the required answer.

If you want the spatial correlation, then you can have to find correlation at every grid using the same function corr2 or you can interpolate into finer grids to get the spatial correlation.

[Anjali Sharma]

Since I don't have the image processing toolbox with me..the corr2 function does not work. I m trying corrcoef but that yields an array. I m interested in single correlation coefficient. Thanks for your reply.

[ANKUR KUMAR]

I have edited my answer. Please go through my edited answer.

[Anjali Sharma]

Yes I too guess corrcoef will do the job. Just to cross-check can you please confirm that the correlation coefficient is same for the matrices you have taken in your example when used with corr2 (I could have done this but i can't!) Thanks in advance.

[ANKUR KUMAR]

Yes, I have cross check and have a faith of MATLAB. Both yield the same answer. Please accept my answer, if it helps you.