• NAME
• SYNOPSIS
• F95 INTERFACE
• C INTERFACE
• PURPOSE
• ARGUMENTS

NAME

ccnvcor - compute the convolution or correlation of complex vectors

SYNOPSIS

  SUBROUTINE CCNVCOR( CNVCOR, FOUR, NX, X, IFX, INCX, NY, NPRE, M, Y, 
 *      IFY, INC1Y, INC2Y, NZ, K, Z, IFZ, INC1Z, INC2Z, WORK, LWORK)
  CHARACTER * 1 CNVCOR, FOUR
  COMPLEX X(*), Y(*), Z(*), WORK(*)
  INTEGER NX, IFX, INCX, NY, NPRE, M, IFY, INC1Y, INC2Y, NZ, K, IFZ, INC1Z, INC2Z, LWORK

  SUBROUTINE CCNVCOR_64( CNVCOR, FOUR, NX, X, IFX, INCX, NY, NPRE, M, 
 *      Y, IFY, INC1Y, INC2Y, NZ, K, Z, IFZ, INC1Z, INC2Z, WORK, LWORK)
  CHARACTER * 1 CNVCOR, FOUR
  COMPLEX X(*), Y(*), Z(*), WORK(*)
  INTEGER*8 NX, IFX, INCX, NY, NPRE, M, IFY, INC1Y, INC2Y, NZ, K, IFZ, INC1Z, INC2Z, LWORK

F95 INTERFACE

  SUBROUTINE CNVCOR( CNVCOR, FOUR, NX, X, IFX, [INCX], NY, NPRE, M, Y, 
 *       IFY, INC1Y, INC2Y, NZ, K, Z, IFZ, INC1Z, INC2Z, WORK, [LWORK])
  CHARACTER(LEN=1) :: CNVCOR, FOUR
  COMPLEX, DIMENSION(:) :: X, Y, Z, WORK
  INTEGER :: NX, IFX, INCX, NY, NPRE, M, IFY, INC1Y, INC2Y, NZ, K, IFZ, INC1Z, INC2Z, LWORK

  SUBROUTINE CNVCOR_64( CNVCOR, FOUR, NX, X, IFX, [INCX], NY, NPRE, M, 
 *       Y, IFY, INC1Y, INC2Y, NZ, K, Z, IFZ, INC1Z, INC2Z, WORK, [LWORK])
  CHARACTER(LEN=1) :: CNVCOR, FOUR
  COMPLEX, DIMENSION(:) :: X, Y, Z, WORK
  INTEGER(8) :: NX, IFX, INCX, NY, NPRE, M, IFY, INC1Y, INC2Y, NZ, K, IFZ, INC1Z, INC2Z, LWORK

C INTERFACE

#include <sunperf.h>

void ccnvcor(char cnvcor, char four, int nx, complex *x, int ifx, int incx, int ny, int npre, int m, complex *y, int ify, int inc1y, int inc2y, int nz, int k, complex *z, int ifz, int inc1z, int inc2z, complex *work, int lwork);

void ccnvcor_64(char cnvcor, char four, long nx, complex *x, long ifx, long incx, long ny, long npre, long m, complex *y, long ify, long inc1y, long inc2y, long nz, long k, complex *z, long ifz, long inc1z, long inc2z, complex *work, long lwork);

PURPOSE

ccnvcor computes the convolution or correlation of complex vectors.

ARGUMENTS

• CNVCOR (input)
  

   CHARACTER

  \'V' or 'v' if convolution is desired, 'R' or 'r' if correlation is desired.

• FOUR (input)
  

   CHARACTER

  \'T' or 't' if the Fourier transform method is to be used, 'D' or 'd' if the computation should be done directly from the definition. The Fourier transform method is generally faster, but it may introduce noticeable errors into certain results, notably when both the real and imaginary parts of the filter and data vectors consist entirely of integers or vectors where elements of either the filter vector or a given data vector differ significantly in magnitude from the 1-norm of the vector.

• NX (input)
  Length of the filter vector. NX > = 0. CCNVCOR will return immediately if NX = 0.

• X (input)
  

   dimension(*)

  Filter vector.

• IFX (input)
  Index of the first element of X. NX > = IFX > = 1.

• INCX (input)
  Stride between elements of the filter vector in X. INCX > 0.

• NY (input)
  Length of the input vectors. NY > = 0. CCNVCOR will return immediately if NY = 0.

• NPRE (input)
  The number of implicit zeros prepended to the Y vectors. NPRE > = 0.

• M (input)
  Number of input vectors. M > = 0. CCNVCOR will return immediately if M = 0.

• Y (input)
  

   dimension(*)

  Input vectors.

• IFY (input)
  Index of the first element of Y. NY > = IFY > = 1.

• INC1Y (input)
  Stride between elements of the input vectors in Y. INC1Y > 0.

• INC2Y (input)
  Stride between the input vectors in Y. INC2Y > 0.

• NZ (input)
  Length of the output vectors. NZ > = 0. CCNVCOR will return immediately if NZ = 0. See the Notes section below for information about how this argument interacts with NX and NY to control circular versus end-off shifting.

• K (input)
  Number of Z vectors. K > = 0. If K = 0 then CCNVCOR will return immediately. If K < M then only the first K input vectors will be processed. If K > M then M input vectors will be processed.

• Z (output)
  

   dimension(*)

  Result vectors.

• IFZ (input)
  Index of the first element of Z. NZ > = IFZ > = 1.

• INC1Z (input)
  Stride between elements of the output vectors in Z. INC1Z > 0.

• INC2Z (input)
  Stride between the output vectors in Z. INC2Z > 0.

• WORK (input/output)
  (input/scratch) dimension(LWORK)

  Scratch space. Before the first call to CCNVCOR with particular values of the integer arguments the first element of WORK must be set to zero. If WORK is written between calls to CCNVCOR or if CCNVCOR is called with different values of the integer arguments then the first element of WORK must again be set to zero before each call. If WORK has not been written and the same values of the integer arguments are used then the first element of WORK to zero. This can avoid certain initializations that store their results into WORK, and avoiding the initialization can make CCNVCOR run faster.

• LWORK (input)
  Length of WORK. LWORK > = 2*MAX(NX,NY,NZ)+8.