Fourier Series of this graph

[Sha]

I've already set up the equation but i can't get this to work. What am I doing wrong?

[RichardJ]

You have the wrong type of summation operator. You need the one that looks like the summation in the first image, with placeholders top and bottom (you can get it with Ctrl Shft 4).

[AlanStevens · Accepted solution]

Because you want odd harmonics only, you will need to change the n's within the sum to (2n-1):

Alan

[Sha]

Hey Alan, thank you for your help, it looks great. One last question so would I have to change the value of N or little n? And is there a way to place the 3rd,5th,7th, etc. harmonic of the waves on the same graph or I can only do that separately?

For example,

y(4,t) = 3rd Harm.

y(6,t) = 5th Harm.

y(8,t) = 7th Harm.

Is that what I should put on the y-axis of plot?

Thank you,

Sha

[ValeryOchkov]

On the Mathcad server:

http://twt.mpei.ac.ru/MCS/Worksheets/Fourier.xmcd

[AlanStevens]

Sha wrote:

Hey Alan, thank you for your help, it looks great. One last question so would I have to change the value of N or little n? And is there a way to place the 3rd,5th,7th, etc. harmonic of the waves on the same graph or I can only do that separately?

For example,

y(4,t) = 3rd Harm.

y(6,t) = 5th Harm.

y(8,t) = 7th Harm.

Is that what I should put on the y-axis of plot?

Thank you,

Sha

You can put more than one on a single graph (just type a comma after the y-axis variable and a new placeholder appears) - I just used separate graphs because the graphs quickly look messy if you overlay several nearly square waves.

You can label them using the "legend" facility - double click on the graph, click the legend box, change the names of the traces.

It's the value of N that you must change. n is a counter within the summation, N is the value it counts to.

Alan

[Werner_E]

Here is an alternative approach.

[ValeryOchkov]

One animation

http://communities.ptc.com/videos/1416