FOURIER SERIES PACKAGE SYMBOL

# NInverseDTFourierTransform

gives a numerical approximation to the inverse discrete time Fourier transform of expr evaluated at the integer n, where expr is a periodic function of with period 1.

## DetailsDetails

• To use , you first need to load the Fourier Series Package using Needs["FourierSeries`"].
• The numerical approximation to the inverse discrete time Fourier transform of expr is by default defined to be NIntegrate[expr n, {, -, }].
• Different choices for the definition of the inverse discrete time Fourier transform can be specified using the option FourierParameters.
• With the setting FourierParameters->{a, b}, expr is assumed to have a period of , and the inverse discrete time Fourier transform computed by is NIntegrate[expr bn, {, -, }].
• The parameter b in the setting FourierParameters->{a, b} must be numeric.
• In addition to the option FourierParameters, can also accept the options available to NIntegrate. These options are passed directly to NIntegrate.

## ExamplesExamplesopen allclose all

### Basic Examples (1)Basic Examples (1)

Numerical value for a sequence with a given discrete time Fourier transform:

 Out[2]=

Compare with the answer from symbolic evaluation:

 Out[3]=
 Out[4]=
 Out[5]=

## TutorialsTutorials

New to Mathematica? Find your learning path »
Have a question? Ask support »