I am trying to make a zeros matrix where certain places is replaced by a 1

I have created a 3x8 matrix of zeroes where i am trying to get place (1,1) and (1,8) and (3,4) to be replaced by ones. so it would look like this:

1 0 0 0 0 0 0 1

0 0 0 0 0 0 0 0

0 0 0 1 0 0 0 0

i have tried to wrote some code for this but i couldn't get it to work.

i have trid this:

b=zeros(3,8)

b([1,3],[1,4,8])=1

but this gives me a matrix that looks like this:

1 0 0 1 0 0 0 1

0 0 0 0 0 0 0 0

1 0 0 1 0 0 0 1

Answer 1

[C B]

b=zeros(3,8);
r = [1 1 3]; % row
c = [1 8 4]; % column
idx = sub2ind(size(b),r,c);
b(idx) = 1;
b

b = 3×8

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

[Helene Maja Graff-Nielsen]

thanks! exactly what i needed!