Reshape cell array into a matrix

I am struggling to reshape this cell array into a matrix of # cell arrays by max length of cell array. This ex 4x7 matrix. The real cell array is much much larger, so I didnt want to loop and build each row.

    a{1} = {1 2 3 4 5}
    a{2} = {2 2 4 5}
    a{3} = {8 2}
    a{4} = {8 2 9 9 2 1 3}

    result = [1 2 3 4 5 0 0;
              2 2 4 5 0 0 0;
              8 2 0 0 0 0 0;
              8 2 9 9 2 1 3]

Answer 1

[Stephen23]

Assuming that those should be numeric vectors:

a{1} = [1 2 3 4 5];
a{2} = [2 2 4 5];
a{3} = [8 2];
a{4} = [8 2 9 9 2 1 3];
v = cellfun('size',a,2);
r = numel(a);
M = zeros(r,max(v));
for k = 1:r
  M(k,1:v(k)) = a{k};
end

Giving:

>> M
M =
   1   2   3   4   5   0   0
   2   2   4   5   0   0   0
   8   2   0   0   0   0   0
   8   2   9   9   2   1   3
>>