Matlab graphing: aligning convolution to a vector

Question

I'm trying to graph a convolution based on a vector.

Here's what I have so far:

>> n=[-10:10];
>> x=zeros(1,length(n));
>> x(n==-1)=1;
>> x(n==0)=1;
>> x(n==1)=-1;
>> u=zeros(1,length(n));
>> u(n>=0)=1;
>> h=(1/2).^n .* u;
>> y = conv(x,h)

Now I want to graph y using stem(n,y) or something like that but y wouldn't be aligned to n anymore as they are different lengths already.

Is there a way to align my old vector n to my new equation y when I'm graphing them? Or at least align my y-values to the right x-axis values.

Answer 1

use:

y= conv(x,h,'same')

This returns the central part of the convolution of the same size as x.