Name

sfst_apply, dfst_apply − Application step for fast sine transform in one dimension

FORMAT

status = {S,D}FST_APPLY (direction, in, out, fst_struct, stride)

Arguments

directioncharacter∗(∗)
Specifies the operation as either the forward or inverse transform. Use Use ’B’ or

in, outreal∗4 | real∗8
Both the arguments are one-dimensional arrays.  The input and output arrays can be the same array. The IN array contains the data to be transformed. The OUT array contains the transformed data.

fst_structrecord /dxml_s_fst_structure/ for single-precision operations
record /dxml_d_fst_structure/ for double-precision operations

strideinteger∗4
Specifies the distance between consecutive elements in the input and output arrays, depending on the value of stride_1_flag provided in the _INIT function. 

Description

The _FST_APPLY functions compute the fast Sine transform of one-dimensional data in three steps. 

Return Values

0DXML_SUCCESS()

12DXML_INS_RES()

13DXML_BAD_STRIDE()

15DXML_BAD_DIRECTION_STRING()

17DXML_OPTION_NOT_SUPPORTED()

Example

INTEGER∗4 N
PARAMETER (N=1024)
INCLUDE ’{file_location}DXMLDEF.FOR’
INTEGER∗4 STATUS
RECORD /DXML_S_FST_STRUCTURE/ D_FST_STRUCT
RECORD /DXML_D_FST_STRUCTURE/ D_FST_STRUCT
REAL∗8 C(1:N),D(1:N)
REAL∗4 E(1:N),F(1:N)
STATUS = DFST_INIT(N,D_FST_STRUCT,1,.TRUE.)
STATUS = DFST_APPLY(’F’,C,D,D_FST_STRUCT,1)
STATUS = DFST_APPLY(’B’,D,C,D_FST_STRUCT,1)
STATUS = DFST_EXIT(D_FST_STRUCT)
STATUS = SFST_INIT(N,S_FST_STRUCT,2,.TRUE.)
STATUS = SFST_APPLY(’F’,E,F,S_FST_STRUCT,1)
STATUS = SFST_APPLY(’B’,F,E,S_FST_STRUCT,1)
STATUS = SFST_EXIT(D_FST_STRUCT)

This FORTRAN code computes the following:

•Forward Type-1 Sine transform of the real sequence C to real sequence D. 

•Backward Type-1 Sine transform of the real sequence D to real sequence C. 

•Forward Type-2 Sine transform of the real sequence E to real sequence F. 

•Backward Type-2 Sine transform of the real sequence F to real sequence E.