Cross validation in matlab between groups

Hi.

I want to make a leave 1 out cross validation (LOOCV) and I have two cells wherein I stored my data. My first cell Original{} is a 1x33 matrix with 1x7 in each. My second cell Predicted{} has the exact same amount of data as Original{}.

How can I make a for loop to take 1 subject out for testing, and 32 for training, 33 times?

I also want to know the R^2 (R-squared) of each of my cross validated values.

Thank you, B!