i want to plot a square wave

the equation is f(t)=(4/k*pi)sin(2*pi*k*t) and k is odd number

[Star Strider]

Please do not post duplicate Questions: http://www.mathworks.com/matlabcentral/answers/249162-i-want-to-plot-a-square-wave

Answer 1

[Geoff Hayes]

Abduladeam - in order to get the square wave, you will have to sum over the odd k (which is missing from your above equation). Also, you need to divide the 4 by (k*pi). Try the following code

 freq = 1;
 func = @(k,t)(4/(k*pi))*sin(2*pi*k*t*freq);
 t    = linspace(0,1,500);
 k    = 1;

 % create a vector for k==1 across all t
 fkt  = func(k,t);

 % now sum over the odd numbers
 upperBound = 100;
 for k=3:2:upperBound
    fkt = fkt + func(k,t);
 end

 plot(t,fkt);

Adjust the freq to increase the frequency of the wave, and increase the upperBound in order to improve upon the square wave's approximation.

[Abduladeam abdullah]

thanks but this is the main equation f(t)=(4/m*pi)sin(2*pi*m*t) m=1,3,5,7,9

and I need to plot the sum of harmonics against time for a time period between 0 and 10

f(t)=(4/pi)sin(2*pi*t)+(4/3*pi)sin(2*pi*3*t)+(4/5*pi)sin(2*pi*5*t)+(4/7*Pi)sin(2*pi*7*t)

[Geoff Hayes]

I'm not sure I understand your question then. Can you not use the above to code for your work?