How to create a matrix of ones and zeros with location of ones based on array that also contains zeros?

Hi,

I have a vector V= [3 1 1 5 0 4], which contains both zeros and nonzero values, I want to obtain a matrix of ones and zeros with location of ones based on vector V. I tried the following code:

V= [3 1 1 5 0 4]

out=zeros(n,m);

m=numel(V);

n=max(V);

out = zeros(n, m);

idx=sub2ind([n m],V,1:m);

out(idx)=1

but I obtained the error: "Error using sub2ind. Out of range subscript".

If I remove the zero from V, the code above works.

My desired result is:

out =

0 1 1 0 0 0

0 0 0 0 0 0

1 0 0 0 0 0

0 0 0 0 0 1

0 0 0 1 0 0

Is it possible to obtain it without a for loop?

Thanks!

Answer 1

[Dyuman Joshi]

You get the error because the code includes 0 as an index.

V = [3 1 1 5 0 4];
idx = V~=0;

m = max(V);
n = numel(V);

R = V;
C = 1:n;

Z = zeros(m,n);
out = sub2ind([m n], R(idx), C(idx));
Z(out) = 1

Z = 5×6

0 1 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 0 0