## Increase nonzero values without deleting zeros

### monmatlab (view profile)

on 12 Apr 2017
Latest activity Commented on by David J. Mack

### David J. Mack (view profile)

on 12 Apr 2017
Accepted Answer by David J. Mack

### David J. Mack (view profile)

I have a vector X.
X=[0 0 0 0 1 1 1 1 0 0 0 0 0 0 2 2 2 2 2 2 0 0 0 3 3 3 3 0 0 0 0 0 4 4 4]
I want to increase the values of the nonzero elements in vector X by 10 However, when I do this using the find function I end up just having a vector without the zeros.
Y=X((find(X~=0)))+10;
Y=[11 11 11 11 22 22 ... ]
Is there a way to do this without using a for loop?

KSSV

### KSSV (view profile)

on 12 Apr 2017
Where you want to place the non zeros numbers?
monmatlab

### monmatlab (view profile)

on 12 Apr 2017
at their initial positions. I want to have the same vector , just with the nonzeros increased by ten

### David J. Mack (view profile)

on 12 Apr 2017
Edited by David J. Mack

### David J. Mack (view profile)

on 12 Apr 2017

Hey monmatlab, simply use logical indexing:
Y = X;
isNonzero = X~=0;
Y(isNonzero) = 10*Y(isNonzero);
or the more compact inplace replacement:
X(X~=0) = 10*X(X~=0);
Greetings, David

on 12 Apr 2017
If this is what you actually want to do, with multiplication then you can just skip the logical part and use
X = X * 10
since multiplying by 0 is 0 anyway! I was under the impression you wanted to add 10, not multiply by it though.
David J. Mack

### David J. Mack (view profile)

on 12 Apr 2017
Ah true, the OP stated to increase it... but it's the same idea anyway. Just replace the * by a +.