MATLAB: How to find the mean after every n columns

column meanscolumn-wisemean

Hi all
In order to find the mean column-wise, I know that we should code as follows:
Answer = nanmean(mymatrix,2); %%mymatrix has many columns %%Answer gives 1 column
Now I have a matrix of size 770 rows x 5760 columns. But I would like to find the mean after EVERY 4 columns and store them in a new matrix. So my final answer matrix will have 770 rows x 1440 columns. How can I do that? Any help is appreciated!
Thank you.

Best Answer

This could be done with a simple for-loop or a slightly trickier reshape:
% Simple data
x = repmat(1:16,3,1)
nrows = 4; % rows to mean
meanby4 = squeeze(nanmean(reshape(x.',nrows,size(x,2)./nrows,[]))).'
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