# FFT Functions

The fast Fourier transform function library of Intel MKL provides one-dimensional, two-dimensional, and multi-dimensional (up to the order of 7) fucntions and both Fortran and C interfaces for all transform functions.

Table “FFT Functions in Intel MKL” lists FFT functions implemented in Intel MKL:

FFT Functions in Intel MKL
Function Name | Operation
--- | ---
Descriptor Manipulation Functions
DftiCreateDescriptor | Allocates memory for the descriptor data structure and preliminarily initializes it.
DftiCommitDescriptor | Performs all initialization for the actual FFT computation.
DftiCopyDescriptor | Copies an existing descriptor.
DftiFreeDescriptor | Frees memory allocated for a descriptor.
FFT Computation Functions
DftiComputeForward | Computes the forward FFT.
DftiComputeBackward | Computes the backward FFT.
Descriptor Configuration Functions
DftiSetValue | Sets one particular configuration parameter with the specified configuration value.
DftiGetValue | Gets the value of one particular configuration parameter.
Status Checking Functions
DftiErrorClass | Checks if the status reflects an error of a predefined class.
DftiErrorMessage | Generates an error message.

Description of the FFT functions is followed by discussion of configuration settings (see Configuration Settings) and various configuration parameters used.