Vectorized implementation for using a vector as an index for matrices

Hello, I have a culumn vector V of m numbers from 1 to 10.

I would like to crate a m x 10 matrix A where in each line i, the V(i) th element is set to 1 and rest to 0.

here's an example of the code I'm trying to vectorize :

    A = zeros(m,10);
    for i=1:m
        A(v(i))=1;
    end

Answer 1

[Stephen23]

Use sub2ind like this:

>> m = 7;
>> V = randi([1,10],1,m)
V =
     9    10     2    10     7     1     3
>> A = zeros(m,10);
>> A(sub2ind(size(A),1:m,V)) = 1
A =
     0     0     0     0     0     0     0     0     1     0
     0     0     0     0     0     0     0     0     0     1
     0     1     0     0     0     0     0     0     0     0
     0     0     0     0     0     0     0     0     0     1
     0     0     0     0     0     0     1     0     0     0
     1     0     0     0     0     0     0     0     0     0
     0     0     1     0     0     0     0     0     0     0
>>