Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 6/24/2024
Public

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?_init_trig_transform

Initializes basic data structures of a Trigonometric Transform.

Syntax

void d_init_trig_transform(MKL_INT *n, MKL_INT *tt_type, MKL_INT ipar[], double dpar[], MKL_INT *stat);

void s_init_trig_transform(MKL_INT *n, MKL_INT *tt_type, MKL_INT ipar[], float spar[], MKL_INT *stat);

Include Files

  • mkl_trig_transforms.f90

Input Parameters

n

MKL_INT*. Contains the size of the problem, which should be a positive integer greater than 1. Note that data vector of the transform, which other TT routines will use, must have size n+1 for all but staggered2 transforms. Staggered2 transforms require the vector of size n.

tt_type

MKL_INT*. Contains the type of transform to compute, defined via a set of named constants. The following constants are available in the current implementation of TT interface: MKL_SINE_TRANSFORM, MKL_STAGGERED_SINE_TRANSFORM, MKL_STAGGERED2_SINE_TRANSFORM; MKL_COSINE_TRANSFORM, MKL_STAGGERED_COSINE_TRANSFORM, MKL_STAGGERED2_COSINE_TRANSFORM.

Output Parameters

ipar

MKL_INT array of size 128. Contains integer data needed for Trigonometric Transform computations.

dpar

double array of size 5n/2+2. Contains double-precision data needed for Trigonometric Transform computations.

spar

float array of size 5n/2+2. Contains single-precision data needed for Trigonometric Transform computations.

stat

MKL_INT*. Contains the routine completion status, which is also written to ipar[6]. The status should be 0 to proceed to other TT routines.

Description

The ?_init_trig_transform routine initializes basic data structures for Trigonometric Transforms of appropriate precision. After a call to ?_init_trig_transform, all subsequently invoked TT routines use values of ipar and dpar (spar) array parameters returned by ?_init_trig_transform. The routine initializes the entire array ipar. In the dpar or spar array, ?_init_trig_transform initializes elements that do not depend upon the type of transform. For a detailed description of arrays ipar, dpar and spar, refer to Common Parameters. You can skip a call to the initialization routine in your code. For more information, see Caveat on Parameter Modifications.

Return Values

stat= 0

The routine successfully completed the task. In general, to proceed with computations, the routine should complete with this stat value.

stat= -99999

The routine failed to complete the task.