How FFT workks? (analytical example)

*To*: mathgroup at smc.vnet.net*Subject*: [mg127424] How FFT workks? (analytical example)*From*: juan miguel <juanmixp at gmail.com>*Date*: Mon, 23 Jul 2012 19:56:32 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net

First of all, thanks for reading my post. Well, the problem is the next one: I have to make an Inverse Fast Fourier Transfrom of a function, but I'm not sure how it works. To do this, I have used a function whose Inverse Fourier Transform is analytical -G f(w)= ------- w+iG/2 So the analytical solution can be easily calculated: Assuming[G > 0,InverseFourierTransform[f[w], w, t]] and the solution is: i Exp(-t G /2)Sqrt(2*pi)G*HeavisideTheta[t] And now I can Plot this function (the imaginary part) Well, what I want is to get exactly the same result using the subrutine Fast Fourier Transfrom (InverseFourier) with that function, but I do not know how to this. It is very important for me, because the function that I have to use has not analytical solution and I have to be sure about what I am doing Thanks