Matlab code for square wave generation from fourier series (symsum fails for upperlimit greater than 1000 in my case)

49 views (last 30 days)
Rishav Raj on 15 Jan 2020
Commented: Rishav Raj on 7 Mar 2020
function [a0,An,Bn]=mysquare(T,N)
syms t n
w0=2*pi/T;
a0=1/T*(int(1,t,0,T/2));
an=2/T*(int(1*cos(n*w0*t),t,0,T/2));
bn=2/T*(int(1*sin(w0*n*t),t,0,T/2));
An=symsum(an.*cos(n*w0*t),n,1,N);
Bn=symsum(bn.*sin(n*w0*t),n,1,N);
%main script
T=4;
[a0,an,bn]=mysquare(T,10000);
ft=a0+an+bn;
fplot(ft);
This works fine for N<=1000 but for larger values it takes alot of time and no result.

Charan Jadigam on 4 Mar 2020
Hi,
The function 'symsum' is trying to find a closed form expression as an answer and it is unable to do so.
Instead, as a workaround, use ‘sum’ function to solve the equation. The usage in your example would be,
An=sum(subs(an.*cos(n*w0*t),n,1:10000));
Bn=sum(subs(bn.*sin(n*w0*t),n,1:10000));
Rishav Raj on 7 Mar 2020
Yes that solved my problem thanks alot!

R2019b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by