# FFT

Advanced Analysis Library Only

AnalysisLibErrType FFT (double arrayXReal[], double arrayXImg[], int numberOfElements);

## Purpose

| Note This function is obsolete. National Instruments recommends that you use CxFFTEx instead.

Calculates the Fast Fourier Transform (FFT) of the complex data.

Let X = x + jy be the complex array:

Y = FFT(X)

FFT can perform the operation in place and overwrite the input arrays.

### Example

/* Generate two arrays with random numbers and calculate the Fast Fourier Transform. */
double x[256], y[256];
n;
n = 256;
Uniform (n, 17, x);
Uniform (n, 17, y);
FFT (x, y, n);

## Parameters

Input
Name | Type | Description
numberOfElements | integer | Number of elements in the input arrays.
Output
Name | Type | Description
arrayXReal | double-precision array | On input, the real part of complex array used to compute the FFT. On output, the real part of the FFT. This operation is performed in place, meaning the values in this array are overwritten.
arrayXImg | double-precision array | On input, the imaginary part of complex array used to compute the FFT. On output, the imaginary part of the 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.