How to do a convolution for n samples starting from n=0 ?

Hi guys,

My question can be a little bit stupid but im trying to figure it out why the answer of my convolution isn't working. The results should appear in the n=0 and this is not what im getting.

Can someone tell me how can i solve it?

The sequence is:

x=[-1 0 1]

h= [0.5 0.25 0.125] ->(version not flipped by the way)

i should get for n=0 ==> -0.5

Cheers!

[Image Analyst]

If n is the number of samples, as you said, then what does it mean when you say n=0? Zero samples????

[Jose Marques]

n is not the number of samples. In discrete convolution, n is a array index.

Answer 1

[Jose Marques]

Hello Jucimar. You can try this:

x = [-1 0 1];
h = [0.5 0.25 0 0.125];

w = conv(x,h)
w =

Columns 1 through 5

   -0.5000   -0.2500    0.5000    0.1250         0

Column 6

    0.1250

[Jose Marques]

For n = 0, the element will be w(1) = -0.5

[Jucimar Carpe]

Hi Jose, so basic i can't have the graphic showing the (n=0) with the amplitude of -0.5 ?

[Jose Marques]

You can generate a array n:

x = [-1 0 1];
h = [0.5 0.25 0 0.125];

n = 0:5;
w = conv(x,h)
plot(n,w)

Try this.

[Jucimar Carpe]

Thats nice!!!, thank you a lot!