Conv two continuous time functions

given y(t) and x(t), it is asked to conv them. Note: x(t)=dirac(t-3)-dirac(t-5). The conv result should sum y(t-3)-y(t-5) but it gives me:

y=@(t) 1.0*(t>=0).*exp(-3*t);
x=@(t) 1.0*(t==3)-1.0*(t==5);

delta=0.0001;
tx=2:delta:6; %tx=(-200:300)*delta;
ty=-1:delta:1.5; % ty=(-100:300)*delta;

c=conv(y(ty),x(tx))*delta;
tc=(tx(1)+ty(1)):delta:(tx(end)+ty(end));

figure()
title('c')
subplot(3,1,1)
plot(tx,x(tx))
xlabel('n'); title('x(t)'); ylim([min(x(tx))-1,max(x(tx))+1]); grid on
subplot(3,1,2)
plot(ty,y(ty))
xlabel('n'); title('h(t)'); ylim([min(y(ty))-1,max(y(ty))+1]); grid on
subplot(3,1,3)
plot(tc,c);
xlabel('n'); title('x(t)*h(t)');ylim([min(c)-1,max(c)+1]); grid on

What can i do to solve the problem?

Thanks

Answer 1

[Thorsten]

The y-axis is too large to show the data. You can rescale them by, e.g.,

 axis([1 8 -delta delta])

or with your code, use

ylim([min(c),max(c)]);

or get rid of the *delta in

c=conv(y(ty),x(tx))*delta;

[DDD]

Thanks Thorsten!

Would you mind to see the question

http://www.mathworks.com/matlabcentral/answers/218768-convolve-two-signals-using-conv-filter-cconv-and-multiplying-in-freq-domain

Thanks once again

Answer 2

[Immanuel Manohar]

Your dirac Delta is wrong... you're attempting continuous time convolution but you are using unit impulse instead of dirac delta for convolution. To get the correct answer, your dirac delta approximation should have the height of 1/delta.

[zhitao Luo]

Hello, Immanuel Manohar, I also encountered the same problem, is there any more detailed answer？