sfct_init, dfct_init 

Initialization step for fast cosine transform in one dimension

FORMAT

  status = {S,D}FCT_INIT (n, fct_struct, type, stride_1_flag)

Arguments

  n                   integer*4
                      Specifies the size of the transform. n must be even and

  fct_struct          record /dxml_s_fct_structure/ for single-precision
                      operations
                      record /dxml_d_fct_structure/ for double-precision
                      operations

  type                integer*4
                      Specifies the type of Cosine transform desired.
                      Currently only type-1 and type-2 transforms are
                      supported.

  stride_1_flag       logical
                      Specifies the allowed distance between consecutive
                      elements in the input and output arrays:

     TRUE: Stride must be 1.

     FALSE: Stride is at least 1.

Description

  The _FCT_INIT functions build internal data structures needed to compute
  fast Cosine transforms of one-dimensional data. These functions are the
  first step in a three-step procedure.  They create the internal data
  structures, using attributes defined in the file CXMLDEF.FOR.

  Use the initialization function that is appropriate for the data format.
  Then use the corresponding application and exit functions to complete the
  transform.  For example, use SFCT_INIT for the internal data structures
  used by SFCT_APPLY and end with the SFCT_EXIT function.

Return Values

  0                  DXML_SUCCESS()

  4                  DXML_ILL_N_IS_ODD()

  8                  DXML_ILL_N_RANGE()

  12                 DXML_INS_RES()

  17                 DXML_OPTION_NOT_SUPPORTED()