RealFFT
From MantidProject
Contents |
Summary
Performs real Fast Fourier Transform
Properties
| Order | Name | Direction | Type | Default | Description |
|---|---|---|---|---|---|
| 1 | InputWorkspace | Input | Workspace2D | Mandatory | The name of the input workspace. |
| 2 | OutputWorkspace | Output | Workspace2D | Mandatory | The name of the output workspace. It will contain two spectra: the real and imaginary parts of the transform. |
| 3 | WorkspaceIndex | Input | integer | Mandatory | The index of the spectrum in the input workspace to transform. |
| 4 | Transform | Input | String | "Forward" | The direction of the transform: "Forward" or "Backward". |
Description
This is an algorithm for Fourier transfom of real data. It uses the GSL routines gsl_fft_real_transform and gsl_fft_halfcomplex_inverse. The result of a forward transform is a two-spectra workspace with the real and imaginary parts of the transform in position 0 and 1 correspondingly. Only positive frequencies are given and as a result the output spectra are twice as short as the input one.
An input workspace for backward transform must have the form of the output workspace of the forward algorithm, i.e. have two spectra with the real part in the first spectrum and the imaginary part in the second one. The output workspace contains a single spectrum with the real inverse transform.
Source Code
Header RealFFT.h
Source RealFFT.cpp
