## Vector inside another vector

### José Campelo (view profile)

on 21 May 2019
Latest activity Commented on by madhan ravi

on 21 May 2019

Hi! I have a vector S = [0 1 2 3 4 ... 30]' and now i want to create another vector U that is equal to 0 if K<S and equal to S if K>=S. In my exercise K=15.
I did this:
U1=zeros(30,1);
U1(15,30)=S;

on 21 May 2019
So U will always be a column vector the same size as 'S' and it will always be either full of 0s or it will match the "S" vector (depending on the value of K which will always be a single number (scalar)). Is that correct?
Alex Mcaulley

### Alex Mcaulley (view profile)

on 21 May 2019
Your problem is not difficult. You just need to take a look to logical indexing in Matlab. For example:
José Campelo

### José Campelo (view profile)

on 21 May 2019
Correct. Basically what I want is that U be a column with 0 until the 14th position and then 15, 16, 17 etc until 30.

### Tags

on 21 May 2019

S =(0:30)';
k = 15;
U = S .* (S>=k);

on 21 May 2019

on 21 May 2019

People don’t do homeworks here. Index K>=S to U1 lhs and S rhs by equating against each other. Since it’s your homework see Alex’s links above and experiment.

on 21 May 2019
My homework detectors didn't go off on this one.

on 21 May 2019
XD sometimes it doesn’t even in mine, maybe a bug xd.