ReInvFFT
Advanced Analysis Library Only
AnalysisLibErrType ReInvFFT (double arrayXReal[], double arrayXImaginary[], ssize_t numberOfElements);
Purpose
 |
Note This function has been superseded by InvFFTEx. |
Calculates the inverse fast Fourier transform (FFT) of a complex sequence that results in a real output array.
Performing an FFT on a real array yields a complex result. The imaginary component array must be at least as large as the real component array.
ReInvFFT performs the operation in place and overwrites the input array. arrayXImg remains unchanged.
Example Code
/* Generate an array with random numbers and calculate its real inverse fast Fourier transform. */
double x[256], y[256];
int n;
n = 256;
Uniform (n, 17, x);
Uniform (n, 17, y);
ReInvFFT (x, y, n);
Parameters
| Input | ||
| Name | Type | Description |
| numberOfElements | ssize_t | Number of elements in the input arrays. |
| Output | ||
| Name | Type | Description |
| arrayX_Real | double [] | On input, the real part of the array used to compute the inverse FFT. arrayXReal must satisfy arrayXReal[i] = arrayXReal[numberOfElements-i], i = 1, 2, …, numberOfElements–1. On output, the real part of the inverse FFT. This operation is performed in place, meaning the values in this array are overwritten. |
| arrayX_Imaginary | double [] | On input, the imaginary part to transform. arrayXImg must satisfy arrayXImg[i] = –arrayXImg[numberOfElements-i], i = 1, 2, …, numberOfElements–1. On output, the imaginary part of the inverse FFT. This operation is performed in place, meaning the values in this array are overwritten. |
Return Value
| Name | Type | Description |
| status | AnalysisLibErrType | A value that specifies the type of error that occurred. Refer to analysis.h for definitions of these constants. |
Additional Information
Library: Advanced Analysis Library
Include file: analysis.h
LabWindows/CVI compatibility: LabWindows/CVI 3.1 and later