code without for loop

Hi,

i have an index variable. Each row contains an x,y coordinate. i can loop through each x,y and set value. but i cannot achieve this without for loop. Can anyone tell me how to run this code without for loop?

for i=1:size(index,1)
    mask(index(i,1),index(i,2)) = 255;
end

Thanks,

Sajid

Answer 1

[Matt Fig]

idx = sub2ind(size(mask),index(:,1),index(:,2));
mask(idx) = 255;