Re: Complex integration

*To*: mathgroup at smc.vnet.net*Subject*: [mg55816] Re: Complex integration*From*: dh <dh at metrohm.ch>*Date*: Thu, 7 Apr 2005 05:09:55 -0400 (EDT)*References*: <d305d3$rv7$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hi Berhard considering your two integrands: 1) 2^(-(-12500 + w)^2/31250 - (-12500 + w + W)^2/ 31250) and 2) 2^(-(-12500 + w)^2/31250 - (-12500 + w + W)^2/ 31250)*E^((-I)*Pi*Cos[(Pi*w)/64] + I*Pi*Cos[(Pi*(w + W))/64]) it is not surprising that the second integral is much more difficult. HOWEVER, if I try to do the second integral, Mathematica simply dies!!! Here my versio of Mathematica: $Version "5.1 for Microsoft Windows (October 25, 2004)" If somebody else could very this we will have a case for WRI Sincerely, Daniel Bernhard von Vacano wrote: > Dear Group, > > I am experiencing problems with a Mathematica simulation I am trying to > perform. > > The first part of my notebook evaluates without any problems: > > > ETL[w_] := Exp[-(w - w0)^2/width^2*2 Log[2]] > > EPer[w_] := ETL[w]* Exp[I Pi Cos[2 Pi w/Wm]] > EPerCC[w_] := ETL[w]* Exp[-I Pi Cos[2 Pi w/Wm]] > > parameter := {w0 -> 12500, width -> 250, Wm -> 128} > > AmpTL[W_] = Integrate[ETL[w]ETL[w + W] /. parameter, {w, 10000, 20000}] > > > This is the first expression I need for plotting (in the Range of W = > 0..1000), and gives the correct results. > With my so far limited mathematica skills, I could not get the following > modified expression to be evaluated: > > AmpPer[W_] = Integrate[EPerCC[w]EPer[w + W] /. parameter, {w, 10000, 20000}] > > Like this, it only produces "$RecursionLimit::reclim: "Recursion depth of > 256 exceeded." und "$IterationLimit::itlim: Iteration limit of 4096 > exceeded." > > I have tried other limits for the integration, indefinite integration and > NIntegrate, but so far it did not work. (At the moment, I am using > Mathematica 4). > > Could anybody help me with this? I don't really know which parameters to use > or how to restate the problem to get it working. It doesn't seem too hard to > compute, does it? > > > Thank you very much in advance, > > Yours > Bernhard > >