insert ones at given position of matrix

I'm stuck on this probably very simple thing - I have this matrix:

rd = zeros(4, 6);

and x is meant to be the position I would like to insert a 1:

x = [3 1 3 1 1 1];

to obtain this:

0 1 0 1 1 1;
0 0 0 0 0 0;
1 0 1 0 0 0;
0 0 0 0 0 0;

Would anybody please be able to help?

Answer 1

[Stephen23]

Use sub2ind:

>> rd = zeros(4,6);
>> x = [3,1,3,1,1,1];
>> rd(sub2ind(size(rd),x,1:numel(x))) = 1
rd =
   0   1   0   1   1   1
   0   0   0   0   0   0
   1   0   1   0   0   0
   0   0   0   0   0   0

[Phillip]

Thank you!