I have a data matrix each for 100 persons.Initially I was dividing columns into four segments (see code below). Now this data matrix vary, instead of 10000, the columns have different lengths. How can i divide them into 4 segments?

data_10_col = data(:,[1:10000]);
for e = 1:4
  epoch(e,:) = data_10_col(1+(e-1)*2500:e*2500);
end

Answer 1

[KSSV]

YOu can use reshape to achieve what you want.

A = rand(100,3) ;   % 100 rows of some data 
[nx,ny] = size(A) ;
B = reshape(A',ny,[],4) ;

iwant = permute(B,[2,1,3]);