Q:

Convert digit to vector octave/matlab

I have a vector y = [0; 2; 4]
I want to convert each element of it into vector, where all elements are zero but element with index equal to digit is 1.
I'd like to do it without loops.
For example [0; 2; 4] should be converted to
[1 0 0 0 0 0 0 0 0 0;
 0 0 1 0 0 0 0 0 0 0;
 0 0 0 0 1 0 0 0 0 0]

(in this example vector first index is 0)

A:

The usual trick with sparse can be used to simplify the process. Let n denote the desired number of columns. Then
result = full(sparse(1:numel(y), y+1, 1, numel(y), n));

For example, y = [0;2;4] and 10 produce
result =
     1     0     0     0     0     0     0     0     0     0
     0     0     1     0     0     0     0     0     0     0
     0     0     0     0     1     0     0     0     0     0

