Subscripted assignment dimension mismatch problem

Hi. I am trying to expand a code. I idea is taken from this link:

http://www.mathworks.com/matlabcentral/answers/31858-how-to-make-the-conversion-more-faster

function [digits,v]=csdigit(num,range,resolution)

Here 'digits' is a string ('0+0-00+0') and 'v' is a double. But when i want to use the above function for a matrix, it's showing error. Here is the code for matrix:

 num_matrix = [1.5675 -4.5632 -1.2376; -6.4542 -5.7162 -2.4316;-5.7601 5.1009 -6.4820];
range = 5;
resolution = 15;
v = zeros(numel(num_matrix),1);
csd = repmat(' ', numel(num_matrix), range + resolution);

 for i = 1: numel(num_matrix)  %Can this loop be vectorized?

    [csd(i,:),v(i)] = csdigit(num_matrix(i), range, resolution); 

 end

While running the above code, it's showing '??? Subscripted assignment dimension mismatch.' error. Can some please help me to solve the problem?

And is there any way to vectorize the above for loop so that it takes less time?