Contents
ccnvcor - compute the convolution or correlation of complex
vectors
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);
ccnvcor computes the convolution or correlation of complex
vectors.
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 signi-
ficantly in magnitude from the 1-norm of the vec-
tor.
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 argu-
ment 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 ele-
ment of WORK to zero. This can avoid certain ini-
tializations 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+NPRE,NZ)+8.