chpr(3P) Sun Performance Library chpr(3P)NAMEchpr - perform the hermitian rank 1 operation A := alpha*x*conjg( x'
) + A
SYNOPSIS
SUBROUTINE CHPR(UPLO, N, ALPHA, X, INCX, A)
CHARACTER * 1 UPLO
COMPLEX X(*), A(*)
INTEGER N, INCX
REAL ALPHA
SUBROUTINE CHPR_64(UPLO, N, ALPHA, X, INCX, A)
CHARACTER * 1 UPLO
COMPLEX X(*), A(*)
INTEGER*8 N, INCX
REAL ALPHA
F95 INTERFACE
SUBROUTINE HPR(UPLO, [N], ALPHA, X, [INCX], A)
CHARACTER(LEN=1) :: UPLO
COMPLEX, DIMENSION(:) :: X, A
INTEGER :: N, INCX
REAL :: ALPHA
SUBROUTINE HPR_64(UPLO, [N], ALPHA, X, [INCX], A)
CHARACTER(LEN=1) :: UPLO
COMPLEX, DIMENSION(:) :: X, A
INTEGER(8) :: N, INCX
REAL :: ALPHA
C INTERFACE
#include <sunperf.h>
void chpr(char uplo, int n, float alpha, complex *x, int incx, complex
*a);
void chpr_64(char uplo, long n, float alpha, complex *x, long incx,
complex *a);
PURPOSEchpr 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.
ARGUMENTS
UPLO (input)
On entry, UPLO specifies whether the upper or lower triangu‐
lar 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 sup‐
plied in A.
UPLO = 'L' or 'l' The lower triangular part of A is sup‐
plied 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 triangular part of the
updated matrix. Before entry with UPLO = 'L' or 'l', the
array A must contain the lower triangular part of the hermit‐
ian 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 ele‐
ments need not be set, they are assumed to be zero, and on
exit they are set to zero.
6 Mar 2009 chpr(3P)
