Assemble of a vector into a matrix

Which is the most effective way of assembling vector v into matrix A, such that matrix A is obtained? (Without using for loops).

v = [1;2;3;4;5;6;7;8;9],

What the assembly is supposed to look like:

A = [1;2;3;0;0;0;0;0;0 , 0;0;0;4;5;6;0;0;0 , 0;0;0;0;0;0;7;8;9].

Matrix A is a 9x3 matrix.

Answer 1

[Guillaume]

v = [1;2;3;4;5;6;7;8;9];
vv  = mat2cell(v, ones(numel(v)/3, 1) * 3, 1);
A = blkdiag(vv{:})