Re: FourierTransform of Sinc Function

*To*: mathgroup at smc.vnet.net*Subject*: [mg44393] Re: FourierTransform of Sinc Function*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Sat, 8 Nov 2003 04:50:38 -0500 (EST)*Organization*: Universitaet Leipzig*References*: <200310281053.FAA25777@smc.vnet.net> <bo7of6$ag8$1@smc.vnet.net> <200311051500.KAA26329@smc.vnet.net> <bofrs7$5gt$1@smc.vnet.net>*Reply-to*: kuska at informatik.uni-leipzig.de*Sender*: owner-wri-mathgroup at wolfram.com

Hi, you should read a book about singnal procesing to understand the difference of a discrete signal and and continuous function. You will never get a top-head function, you many only get better discrete approximations to a top-head function. Regards Jens Kieng wrote: > > I am sorry my question is apparently not so clear. > I generated a list of data from a sinc function. I am not doing the > transform from the sinc function. > If I use Fourier[list of the data], and plot the result, her is where I am > kind of not sure why I don't get a top hat function, even though I used very > fine step for my sinc function data. > > ----- Original Message ----- > From: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de> To: mathgroup at smc.vnet.net > Subject: [mg44393] Re: FourierTransform of Sinc Function > > > Hi, > > > > what is mysterious on > > > > In[]:=FourierTransform[Sin[w*x]/x, x, k] > > > > Out[]=(Sqrt[Pi/2]*(-Sign[k - w] + Sign[k + w]))/2 > > > > Regards > > Jens > > > > Kieng wrote: > > > > > > Dear All, > > > > > > I tested the Fourier Function on a sinc function which should give the > > > top-hat but mathatmatica gave some mysterious plot that I don't > understand. > > > Anyone knows what is going on. > > > > > > Thank you very much, > > > Sorasak > >

**References**:**Re: FourierTransform of Sinc Function***From:*Jens-Peer Kuska <kuska@informatik.uni-leipzig.de>