How do I take the average of every n values in a matrix?

hello again, i have one a2_dap_U 17567x71x42 double value matrix; 17567=values every 30 min, 71x42 grid.

so i tried this one for the 24 hour average (48 since its every 30 min):

a2_dap_U_24=arrayfun(@(i) nanmean(a2_dap_U(i:i+48-1)),1:48:length(a2_dap_U)-48+1)';

but it gave me 365 NaN values, and i dont know how to do it, since this command line help me with individual values that i extracted from two sites within the 71x42 matrix, but it doesnt help me for the whole 17567 values for the whole matrix.

any help please ;)

Answer 1

[Matt J]

   a2_dap_U(17568,:,:)=nan; %pad to even multiple of 48

   A=nanmean(reshape(a2_dap_U,48,[]));
   B=reshape(A,[],71,42);