Replace elements of array with elements of another array without for loop

A = [1 1 1 3 3 3 4 8 8 10 10 15 15]

B = unique(A)

B = [1 3 4 8 10 15]

I want the output to be [1 1 1 2 2 2 3 4 4 5 5 6 6]

I tried for loop :

for i=1:length(A)

A(A == B(i)) = i;

end

How can I do it without for loop?

Answer 1

[Birdman]

 [B,ia,ic] = unique(A)

Third output argument ic will give you what you want.

[Guillaume]

So really in this case, since the first two outputs are not needed:

 [~, ~, B] = unique(A);