Discrete convolution.

Hi, im trying to make certain examples of convolution codes for a function with N elements. so far I have done this. But I wish to find out a way so that it can be implemented on C too. any ideas or help?

clear all; close all; clc

x=[1 2 3]
h=[-1 0 3]
Z=[0]
[M,N]=size(x)
[L,O]=size(h)
a=1
A=N+O-1
suma=[0]
for n=1:1:N
    for o=1:1:O
        y(n,o)=x(n)*h(o)

      end 
end
s=fliplr(y);
n=-1*(N-1);
for r=1:A
    Yfor(r)=sum(diag(s,n))
    n=n+1;
end
Yconv=fliplr(Yfor)
%Yfor=0
%Yfor(1)=y(1,1)
%Yfor(2)=y(2,1)+y(1,2)
%Yfor(3)=y(3,1)+y(2,2)+y(1,3)
%Yfor(4)=y(3,2)+y(2,3)
%Yfor(5)=y(3,3)
Y=conv(x,h)
figure, stem(x)
grid on

figure,stem(Yconv) grid on

[Image Analyst]

Any reason why you're not using the built-in conv() function?

[Walter Roberson]

Everything other than the conv() and the graphics should be easy to do in C.

For example, since you do not use s after taking the diag() of it, you can just design your equivalent to diag to index right to left instead of left to right.