How to assign the value of the index to the index position?

Hello dear Matlab Community

I have a row vector with the size of 1x40000. The vector consists of zeros and ones.

How can i convert the value ones to the value of their corresponding indices?

Here is a small example

v = [0 0 0 1 1 1 0 0 0]; % This vector ones at positions 4,5, and 6, and I want that the ones get changed by the values 4,5, and 6.

Thank you in advance,

Paul

Answer 1

[KSSV]

v = [0 0 0 1 1 1  0 0 0];
idx = find(v)

idx = 1×3

4 5 6

v(v==1) = find(v)

v = 1×9

0 0 0 4 5 6 0 0 0

[Paul Hinze]

Perfect, thank you

[KSSV]

Thanks is accepting the answer .. :)