I have a 2D vector which contains the coordinates which I want to represent as True or one in a matrix with dimensions nxm. Can I build this matrix without a loop?
Your assignment to points is syntactically incorrect, it should be:
points=[1,30,8;1,20,7];
The solution to you problem lies in converting subscripts to linear indices with sub2ind:
sub2ind
grid(sub2ind(size(grid),points(1,:),points(2,:)))=1