Re: Fourier coefficients
- To: mathgroup at smc.vnet.net
- Subject: [mg32947] Re: [mg32935] Fourier coefficients
- From: BobHanlon at aol.com
- Date: Thu, 21 Feb 2002 02:06:59 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
In a message dated 2/20/02 2:31:21 AM, phil at icu.strath.ac.uk writes:
>I am trying to do something really "simple". I want to Plot the Fourier
>
>coefficients as vertical lines. The line height should be proportional
>
>to the magnitude of its respective coefficient. I just can't seem to
>get it though. Any ideas?
>
Needs["Calculus`FourierTransform`"];
Needs["Graphics`Colors`"];
FourierTrigSeries[t, t, 5]
Sin[2*Pi*t]/Pi - Sin[4*Pi*t]/(2*Pi) + Sin[6*Pi*t]/(3*Pi) -
Sin[8*Pi*t]/(4*Pi) + Sin[10*Pi*t]/(5*Pi)
m=8;
coef = Table[FourierSinCoefficient[t, t, n], {n,m}]
{1/Pi, -(1/(2*Pi)), 1/(3*Pi), -(1/(4*Pi)), 1/(5*Pi),
-(1/(6*Pi)), 1/(7*Pi), -(1/(8*Pi))}
Plot[{1/(n*Pi),-1/(n*Pi), Sin[(2n-1)*Pi/2]/(n*Pi)},
{n,1,m},
PlotStyle->{
{Green,AbsoluteDashing[{2,5}]},
{Green,AbsoluteDashing[{2,5}]},
{Blue,AbsoluteDashing[{5,5,2,5}]}},
Frame -> True,
Epilog->{Red,
Table[
Line[{{n,0},{n,coef[[n]]}}],
{n,m}]}];
Bob Hanlon
Chantilly, VA USA