Fourier series neither odd nor even

  • #1
69
0

Homework Statement


I'm trying to calculate the Fourier Series for a periodic signal defined as:

y = x 0<x<2Π
y = 0 2Π≤x<3Π

Homework Equations


Fn = 1/T ∫T f(t)cos(kwοt + θk)[/B]
cn/2 + ∑k=1k=∞(cn)cos(kwοt+θk)
cn= 2|Fn|
θk=∠Fn

The Attempt at a Solution


I got Cn = -(√3/ +9/4Π)
θk = -kwοt

The problem with this value for θk is that k disappears from the summation. I need this formula to be able to regenerate the original signal from it's fourier series coefficients using matlab. I must be doing something wrong. I would really appreciate it if someone told me what to do.
 
Last edited:

Answers and Replies

  • #2
Simon Bridge
Science Advisor
Homework Helper
17,857
1,655
Try using a more general fourier series with both sine and cosine in it.
Looking at your function - is it better served by a sum of cosines or a sum of sines?
 
  • #3
69
0
Try using a more general fourier series with both sine and cosine in it.
Looking at your function - is it better served by a sum of cosines or a sum of sines?
My function is neither odd nor even so it has to be represented using both sines and cosines right?
I thought the formula I'm using above works fine for all real functions. In fact the first part of the question asked me to prove this.
I'll try using the general form anyway and post the results.
 
  • #4
rude man
Homework Helper
Insights Author
Gold Member
7,871
793
My function is neither odd nor even so it has to be represented using both sines and cosines right?
I thought the formula I'm using above works fine for all real functions.
You're quite right, in that form it can represent any real periodic function.
But you haven't defined your function too well. Does it repeat below x=0 and above x=3pi?
 

Related Threads on Fourier series neither odd nor even

  • Last Post
2
Replies
26
Views
2K
  • Last Post
Replies
0
Views
7K
Replies
2
Views
481
Replies
17
Views
3K
Replies
0
Views
1K
Replies
4
Views
3K
Replies
8
Views
1K
  • Last Post
Replies
6
Views
1K
  • Last Post
Replies
4
Views
1K
Top