DftiComputeForward
DftiComputeForward
Computes the forward FFT.
Syntax
status
=
DftiComputeForward
(
desc_handle
,
x_inout
)
;
status
=
DftiComputeForward
(
desc_handle
,
x_in
,
y_out
)
;
status
=
DftiComputeForward
(
desc_handle
,
xre_in
out,
xim_inout
)
;
status
=
DftiComputeForward
(
desc_handle
,
xre_in
,
xim_in
,
yre_out
,
yim_out
)
;
Input Parameters
Name | Type | Description |
|---|---|---|
desc_handle
| DFTI_DESCRIPTOR_HANDLE | FFT descriptor. |
x_inout, x_in | Array of type float or double depending on the precision of the transform, specified in the DFTI_PRECISION configuration setting. | Data to be transformed in case of a real forward domain, specified in the DFTI_FORWARD_DOMAIN configuration setting. |
xre_inout, xim_inout, xre_in, xim_in
| Array of type float or double depending on the precision of the transform. | Real and imaginary parts of the data to be transformed in the case of a complex forward domain, specified in the DFTI_FORWARD_DOMAIN configuration setting. |
The suffix in parameter names corresponds to the value of the configuration parameter
DFTI_PLACEMENT
as follows:- _inouttoDFTI_INPLACE
- _intoDFTI_NOT_INPLACE
Output Parameters
Name | Type | Description |
|---|---|---|
y_out | Array of type float or double depending on the precision of the transform. | The transformed data in case of a real backward domain, determined by the DFTI_FORWARD_DOMAIN configuration setting. |
xre_inout, xim_inout, yre_out, yim_out
| Array of type float or double depending on the precision of the transform. | Real and imaginary parts of the transformed data in the case of a complex backward domain, determined by the DFTI_FORWARD_DOMAIN configuration setting. |
status
| MKL_LONG | Function completion status. |
The suffix in parameter names corresponds to the value of the configuration parameter
DFTI_PLACEMENT
as follows:- _inouttoDFTI_INPLACE
- _outtoDFTI_NOT_INPLACE
Include Files
- mkl.h
Description
The = -1.
DftiComputeForward
function accepts the descriptor
handle parameter and one or more data
parameters.
Given a successfully configured and committed descriptor, this function computes the forward FFT, that is, the transform with the minus sign in the exponent, δ
The
DFTI_COMPLEX_STORAGE, DFTI_REAL_STORAGE
, and DFTI_CONJUGATE_EVEN_STORAGE
configuration parameters define the layout of the input and output data and must be properly set in a call to the DftiSetValue
function.The FFT descriptor must be properly configured prior to the function call. Function calls needed to configure an FFT descriptor for a particular call to an FFT computation function are summarized in Configuring and Computing an FFT in C C++.
The number and types of the data parameters that the function requires may vary depending on the configuration of the
descriptor. This variation is accommodated by
variable parameters
.The function returns zero when it completes successfully.
See Status Checking Functions for more information on the returned status.
Prototype
MKL_LONG DftiComputeForward( DFTI_DESCRIPTOR_HANDLE, void*, ... );