Contents
zhpr - perform the hermitian rank 1 operation A :=
alpha*x*conjg( x' ) + A
SUBROUTINE ZHPR(UPLO, N, ALPHA, X, INCX, A)
CHARACTER * 1 UPLO
DOUBLE COMPLEX X(*), A(*)
INTEGER N, INCX
DOUBLE PRECISION ALPHA
SUBROUTINE ZHPR_64(UPLO, N, ALPHA, X, INCX, A)
CHARACTER * 1 UPLO
DOUBLE COMPLEX X(*), A(*)
INTEGER*8 N, INCX
DOUBLE PRECISION ALPHA
F95 INTERFACE
SUBROUTINE HPR(UPLO, [N], ALPHA, X, [INCX], A)
CHARACTER(LEN=1) :: UPLO
COMPLEX(8), DIMENSION(:) :: X, A
INTEGER :: N, INCX
REAL(8) :: ALPHA
SUBROUTINE HPR_64(UPLO, [N], ALPHA, X, [INCX], A)
CHARACTER(LEN=1) :: UPLO
COMPLEX(8), DIMENSION(:) :: X, A
INTEGER(8) :: N, INCX
REAL(8) :: ALPHA
C INTERFACE
#include <sunperf.h>
void zhpr(char uplo, int n, double alpha, doublecomplex *x,
int incx, doublecomplex *a);
void zhpr_64(char uplo, long n, double alpha, doublecomplex
*x, long incx, doublecomplex *a);
zhpr performs the hermitian rank 1 operation A :=
alpha*x*conjg( x' ) + A where alpha is a real scalar, x is
an n element vector and A is an n by n hermitian matrix,
supplied in packed form.
UPLO (input)
On entry, UPLO specifies whether the upper or
lower triangular part of the matrix A is supplied
in the packed array A as follows:
UPLO = 'U' or 'u' The upper triangular part of A
is supplied in A.
UPLO = 'L' or 'l' The lower triangular part of A
is supplied in A.
Unchanged on exit.
N (input)
On entry, N specifies the order of the matrix A.
N >= 0. Unchanged on exit.
ALPHA (input)
On entry, ALPHA specifies the scalar alpha.
Unchanged on exit.
X (input)
( 1 + ( n - 1 )*abs( INCX ) ). Before entry, the
incremented array X must contain the n element
vector x. Unchanged on exit.
INCX (input)
On entry, INCX specifies the increment for the
elements of X. INCX <> 0. Unchanged on exit.
A (input/output)
( ( n*( n + 1 ) )/2 ). Before entry with UPLO =
'U' or 'u', the array A must contain the upper
triangular part of the hermitian matrix packed
sequentially, column by column, so that A( 1 )
contains a( 1, 1 ), A( 2 ) and A( 3 ) contain a(
1, 2 ) and a( 2, 2 ) respectively, and so on. On
exit, the array A is overwritten by the upper tri-
angular part of the updated matrix. Before entry
with UPLO = 'L' or 'l', the array A must contain
the lower triangular part of the hermitian matrix
packed sequentially, column by column, so that A(
1 ) contains a( 1, 1 ), A( 2 ) and A( 3 ) contain
a( 2, 1 ) and a( 3, 1 ) respectively, and so on.
On exit, the array A is overwritten by the lower
triangular part of the updated matrix. Note that
the imaginary parts of the diagonal elements need
not be set, they are assumed to be zero, and on
exit they are set to zero.