Developer Reference

Contents

?_forward_trig_transform

Computes the forward Trigonometric Transform of type specified by the parameter.

Syntax

void d_forward_trig_transform
(
double
f[],
DFTI_DESCRIPTOR_HANDLE
*handle,
MKL_INT
ipar[],
double
dpar[],
MKL_INT
*stat
)
;
void s_forward_trig_transform
(
float
f[],
DFTI_DESCRIPTOR_HANDLE
*handle,
MKL_INT
ipar[],
float
spar[],
MKL_INT
*stat
)
;
Include Files
  • mkl.h
Input Parameters
f
double
for
d_forward_trig_transform
,
float
for
s_forward_trig_transform
,
array of size
n
for staggered2 transforms and of size
n
+1 for all other transforms, where
n
is the size of the problem. On input, contains data vector to be transformed. Note that the following values should be 0.0 up to rounding errors:
  • f
    [0] and
    f
    [
    n
    ] for sine transforms
  • f
    [
    n
    ] for staggered cosine transforms
  • f
    [0] for staggered sine transforms.
Otherwise, the routine will produce a warning, and the result of the computations for sine transforms may be wrong. The above restrictions meet the requirements of the
Intel® MKL
Poisson Solver, which the TT interface is primarily designed for (for details, seeFast Poisson Solver Routines).
handle
DFTI_DESCRIPTOR_HANDLE*
. The data structure used by
Intel® MKL
FFT interface (for details, seeFFT Functions).
ipar
MKL_INT
array of size 128. Contains integer data needed for Trigonometric Transform computations.
dpar
double
array of size 5
n
/2+2. Contains double-precision data needed for Trigonometric Transform computations.
spar
float
array of size 5
n
/2+2. Contains single-precision data needed for Trigonometric Transform computations.
Output Parameters
f
Contains the transformed vector on output.
ipar
Contains integer data needed for Trigonometric Transform computations. On output,
ipar[6]
is updated with the
stat
value.
stat
MKL_INT*
. Contains the routine completion status, which is also written to
ipar[6]
.
Description
The routine computes the forward Trigonometric Transform of type defined in the
?_init_trig_transform
routine and passed to
?_forward_trig_transform
with the
ipar
array. The size of the problem
n
, which determines sizes of the array parameters, is also passed to the routine with the
ipar
array and defined in the previously called
?_init_trig_transform
routine. The other data that facilitates the computation is created by
?_commit_trig_transform
and supplied in
dpar
or
spar
. For a detailed description of arrays
ipar
,
dpar
and
spar
, refer to Common Parameters. The routine has a commit step, which calls the
?_commit_trig_transform
routine. The transform is computed according to formulas given in Transforms Implemented. The routine replaces the input vector
f
with the transformed vector.
If you need a copy of the data vector
f
to be transformed, make the copy before calling the
?_forward_trig_transform
routine.
Return Values
stat
= 0
The routine completed the task normally.
stat
= -100
The routine stopped for any of the following reasons:
  • An error in the user's data was encountered.
  • Data in
    ipar
    ,
    dpar
    or
    spar
    parameters became incorrect and/or inconsistent as a result of modifications.
stat
= -1000
The routine stopped because of an FFT interface error.
stat
= -10000
The routine stopped because its commit step failed to complete or the parameter
ipar[0]
was altered by mistake.

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804