MathGroup Archive 2005

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Extract Coefficients of Fourier Series


Hi

In order to illustrate how I went about this I created some random data
and TrigFit returned something like this.

0.576739 + 0.128598 Cos[x] + 0.0328485
  Cos[2 x] - 0.018517 Cos[3 x] + 0.0484222 Cos[4 x]

So I call this functiuon fit[x] -

fit[x_]:=0.576739 + 0.128598 Cos[x] + 0.0328485
  Cos[2 x] - 0.018517 Cos[3 x] + 0.0484222 Cos[4 x]

The constant term I get by doing
const = fit[x][[1]];

the rest of the terms I get using a loop:

Do[
  coeff = fit[x][[n]][[1]];
  Print[coeff];
  , {n, 2, Length[fit[x]]}
  ]

which should print out the coefficients.  I'll leave it to you to
modify the loop so instead of printing them you square and add them up.

hope this helps

Mike


  • Prev by Date: Re: "2p" in BenchmarkReport[] ?
  • Next by Date: Re: Symbolic Constrained Maximization
  • Previous by thread: Re: Extract Coefficients of Fourier Series
  • Next by thread: Re: Extract Coefficients of Fourier Series