Create matrix using the array as index

Hi,

I have an array of 1*2000 double. I want to create matrix of 6*2000 double. so only the index of the value is 1 and the others is zero in each columns.

for example if my array is a=[2 2 1 0 3]

the ouput of of matrix will be same as the image below?

Thank you.

Answer 1

[Rik]

You don't even need a loop:

a=[2 2 1 0 3];

ind=a+1;
A=zeros(max(ind),numel(ind));
ind=sub2ind(size(A),ind,1:numel(ind));
A(ind)=1

A = 4×5

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

Answer 2

[per isakson]

Try this

M = zeros(5,5);
a = [2,2,1,0,3];
for jj = 1:5
    M(a(jj)+1,jj)=1; 
end
disp(M)

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