dgthrz(3P) Sun Performance Library dgthrz(3P)NAMEdgthrz - Gather and zero.
SYNOPSIS
SUBROUTINE DGTHRZ(NZ, Y, X, INDX)
DOUBLE PRECISION Y(*), X(*)
INTEGER NZ
INTEGER INDX(*)
SUBROUTINE DGTHRZ_64(NZ, Y, X, INDX)
DOUBLE PRECISION Y(*), X(*)
INTEGER*8 NZ
INTEGER*8 INDX(*)
F95 INTERFACE
SUBROUTINE GTHRZ([NZ], Y, X, INDX)
REAL(8), DIMENSION(:) :: Y, X
INTEGER :: NZ
INTEGER, DIMENSION(:) :: INDX
SUBROUTINE GTHRZ_64([NZ], Y, X, INDX)
REAL(8), DIMENSION(:) :: Y, X
INTEGER(8) :: NZ
INTEGER(8), DIMENSION(:) :: INDX
C INTERFACE
#include <sunperf.h>
void dgthrz (const int nz, double* y, double* x, const int* indx);
void dgthrz_64 (const long nz, double* y, double* x, const long* indx);
PURPOSE
DGTHRZ - Gathers the specified elements from a vector y in full storage
form into a vector x in compressed form. The gathered elements of y
are set to zero. Only the elements of y whose indices are listed in
indx are referenced.
do i = 1, n
x(i) = y(indx(i))
y(indx(i)) = 0
enddo
ARGUMENTS
NZ (input) - INTEGER
Number of elements in the compressed form. Unchanged on exit.
Y (input/output)
Vector in full storage form. Gathered elements are set to
zero.
X (output)
Vector in compressed form. Contains elements of y whose
indices are listed in indx on exit.
INDX (input) - INTEGER
Vector containing the indices of the compressed form. It is
assumed that the elements in INDX are distinct and greater than
zero. Unchanged on exit.
3rd Berkeley Distribution 6 Mar 2009 dgthrz(3P)
