Plotting cycles of signal

z(t) = ( t if − π ≤ t < 0 )

( 1 if 0 ≤ t ≤ π )

How do i plot 3 cycles of the above signal and find the fourier series

Answer 1

[Surya Talluri]

I understand that you want to plot 3 periods of the signal and obtain its Fourier Series.

t = [-pi:0.1:0 0:0.1:pi];
z = [-pi:0.1:0 ones([1, numel(0:0.1:pi)])];

t3 = [t t(2:end)+2*pi t(2:end)+4*pi];
z3 = [z z(2:end) z(2:end)];

plot(t3,z3)
ylim([-pi, pi])
xlim([-pi, 5*pi])
grid on 

You can obtain Fourier series coefficients of a signal by using fit function in our Curve Fitting Toolbox or by using Curve Fitting App.

f = fit(t3',z3', 'fourier8'); 
plot(f, t3, z3) 

You can find the fourier coefficients and their values with coeffnames and coeffvalues functions.

You can access the following documentation for further understanding:

• Fourier Series - https://www.mathworks.com/help/curvefit/fourier.html
• Fit function - https://www.mathworks.com/help/curvefit/fit.html