Output looped values to the same array/matrix

Basically, I have the code below. I want to generate 2 output files, one for B and one for PVAL, each of which should contain the outputs for each loop so I am left with 1 sheet containing all of the B values for each loop, and another sheet containing all of the PVAL values for each loop.

What do I need to add to the code to achieve this?

 for i = 1:size(data,1)/8
        xx=data(8*i-7:8*i,2:3); yy=data(8*i-7:8*i,1);
        [B,SE,PVAL,INMODEL,STATS,NEXTSTEP,HISTORY]=stepwisefit(xx,yy,'penter',.05);
        end

Thanks in advance for any help!

Answer 1

[Guillaume]

You just need to predeclare your B and PVAL with the appropriate size and use your i index to put the result of stepwisefit in the relevant column:

numsteps = size(data, 1)/8;
B = zeros(2, numsteps);
PVAL = zeros(2, numsteps);
for i = 1:numsteps
   xx=data(8*i-7:8*i,2:3); yy=data(8*i-7:8*i,1);
   [B(:, i), ~, PVAL(:, i)] = stepwisefit(xx, yy, 'penter', .05)
end