Thread: Plotting Fourier series approximation for a square wave using MATLAB.

Suppose is a square wave of period such that

for

for

The Fourier series for is



I tried plotting this using MATLAB (using the first 10 terms):

Code:

x=linspace(-4*pi,4*pi,100);
y=0;
k=1;
    for n=1:10
        y=y+4*sin(k*x)/pi*k;
        k=k+2;
    end
plot(x,y)
axis([-4*pi 4*pi -2 2])
xlabel('x')
ylabel('Square wave approximation using first 10 terms')

I have attached my output but it doesn't look anything like a square wave. What am I doing wrong?

Hi alexmahone!


Perhaps you should write

y=y+4*sin(k*x)/(pi*k);

instead of:

y=y+4*sin(k*x)/pi*k;

Originally Posted by ILikeSerena

Hi alexmahone!


Perhaps you should write

y=y+4*sin(k*x)/(pi*k);

instead of:

y=y+4*sin(k*x)/pi*k;

You are just amazing!

I now get: