Portability	portable
Stability	experimental
Maintainer	[email protected]
Safe Haskell	None

Statistics.Transform

Contents

Type synonyms
Discrete cosine transform
Fast Fourier transform

Description

Fourier-related transformations of mathematical functions.

These functions are written for simplicity and correctness, not speed. If you need a fast FFT implementation for your application, you should strongly consider using a library of FFTW bindings instead.

Synopsis

Type synonyms

type CD = Complex Double Source

Discrete cosine transform

dct :: Vector Double -> Vector Double Source

Discrete cosine transform (DCT-II).

dct_ :: Vector CD -> Vector Double Source

Discrete cosine transform (DCT-II). Only real part of vector is transformed, imaginary part is ignored.

idct :: Vector Double -> Vector Double Source

Inverse discrete cosine transform (DCT-III). It's inverse of dct only up to scale parameter:

 (idct . dct) x = (* length x)

idct_ :: Vector CD -> Vector Double Source

Inverse discrete cosine transform (DCT-III). Only real part of vector is transformed, imaginary part is ignored.

Fast Fourier transform

fft :: Vector CD -> Vector CD Source

Radix-2 decimation-in-time fast Fourier transform.

ifft :: Vector CD -> Vector CD Source

Inverse fast Fourier transform.