Fourier series with Mathematica. Help!
- To: mathgroup at smc.vnet.net
- Subject: [mg12779] Fourier series with Mathematica. Help!
- From: Peter Neumann <peter at iei.tu-clausthal.de>
- Date: Wed, 10 Jun 1998 03:04:39 -0400
- Organization: Rechenzentrum der TU Clausthal
- Sender: owner-wri-mathgroup at wolfram.com
I've got problems to calculate FourierTrigSeries from periodic functions
containing UnitStep-Expressions under Mathematica 3.0. (I now I have
to load <<Calculus`DiracDelta` first.)
I attached an example file containung two examples. The first, a
rectangular function using UnitStep, causes no proplems. The second
example combining Sin and UnitStep fails to integrate. But the
integration could be done easily by hand.
Can anybody help me?
************ InputForm ******************
<<Calculus`FourierTransform`
<<Calculus`DiracDelta`
f1 = UnitStep[t-Pi/4] - UnitStep[t-3*Pi/4]
-UnitStep[t-5*Pi/4] + UnitStep[t-7*Pi/4];
Plot[f1,{t,0,2*Pi}]
FourierTrigSeries[f1, {t,0,2*Pi}, 5]
f2 = (1+3*Sin[t])*UnitStep[-1-3*Sin[t]]
+(-1+3*Sin[t])*UnitStep[-1+3*Sin[t]];
Plot[f2, {t,0,2*Pi}]
FourierTrigSeries[f2, {t,0,2*Pi}, 5]
************ End of Example *****************