How can I divide a matrix by its columns ?

Question

Andre 2014-4-23

编辑： the cyclist 2014-4-23

Hi,

for example:

[ 1  35  37 29 312
  1 321 421  2  34
  1 329 412 32  54
.
.
.
  4 421 348 48 445
  4  48  49 41 394 ]

Can I segregate this matrix in small matrix based on the first column ?

Example:

A = [ 1  35  37 29 312
      1 321 421  2  34
      1 329 412 32  54]
B =...
C =...
D = [ 4 421 348 48 445
      4  48  49 41 394 ]

Andre

Answer 1

the cyclist 2014-4-23

编辑：the cyclist 2014-4-23

Yes, use the accepted answer from Azzi that is posted here. Just choose the 1st column instead of the 4th column.

Namely, if your original matrix is called A, then

[ii,jj,kk] = unique(A(:,1))
out = accumarray(kk,1:numel(kk),[],@(x) {A(x,:)})
celldisp(out)

You will see that "out" is a cell array, where each cell has one of the smaller matrices you want.