cher2
cher2 - perform the hermitian rank 2 operation A := alpha*x*conjg( y' ) + conjg( alpha )*y*conjg( x' ) + A
SUBROUTINE CHER2( UPLO, N, ALPHA, X, INCX, Y, INCY, A, LDA)
CHARACTER * 1 UPLO
COMPLEX ALPHA
COMPLEX X(*), Y(*), A(LDA,*)
INTEGER N, INCX, INCY, LDA
SUBROUTINE CHER2_64( UPLO, N, ALPHA, X, INCX, Y, INCY, A, LDA)
CHARACTER * 1 UPLO
COMPLEX ALPHA
COMPLEX X(*), Y(*), A(LDA,*)
INTEGER*8 N, INCX, INCY, LDA
SUBROUTINE HER2( UPLO, [N], ALPHA, X, [INCX], Y, [INCY], A, [LDA])
CHARACTER(LEN=1) :: UPLO
COMPLEX :: ALPHA
COMPLEX, DIMENSION(:) :: X, Y
COMPLEX, DIMENSION(:,:) :: A
INTEGER :: N, INCX, INCY, LDA
SUBROUTINE HER2_64( UPLO, [N], ALPHA, X, [INCX], Y, [INCY], A, [LDA])
CHARACTER(LEN=1) :: UPLO
COMPLEX :: ALPHA
COMPLEX, DIMENSION(:) :: X, Y
COMPLEX, DIMENSION(:,:) :: A
INTEGER(8) :: N, INCX, INCY, LDA
#include <sunperf.h>
void cher2(char uplo, int n, complex alpha, complex *x, int incx, complex *y, int incy, complex *a, int lda);
void cher2_64(char uplo, long n, complex alpha, complex *x, long incx, complex *y, long incy, complex *a, long lda);
cher2 performs the hermitian rank 2 operation
A := alpha*x*conjg( y' ) + conjg( alpha )*y*conjg( x' ) + A
where alpha is a scalar, x and y are n element vectors and A is an n
by n hermitian matrix.
-
* UPLO (input)
-
On entry, UPLO specifies whether the upper or lower
triangular part of the array A is to be referenced as
follows:
UPLO = 'U' or 'u' Only the upper triangular part of A
is to be referenced.
UPLO = 'L' or 'l' Only the lower triangular part of A
is to be referenced.
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.
-
* Y (input)
-
( 1 + ( n - 1 )*abs( INCY ) ).
Before entry, the incremented array Y must contain the n
element vector y.
Unchanged on exit.
-
* INCY (input)
-
On entry, INCY specifies the increment for the elements of
Y. INCY <> 0.
Unchanged on exit.
-
* A (input/output)
-
Before entry with UPLO = 'U' or 'u', the leading n by n
upper triangular part of the array A must contain the upper
triangular part of the hermitian matrix and the strictly
lower triangular part of A is not referenced. On exit, the
upper triangular part of the array A is overwritten by the
upper triangular part of the updated matrix.
Before entry with UPLO = 'L' or 'l', the leading n by n
lower triangular part of the array A must contain the lower
triangular part of the hermitian matrix and the strictly
upper triangular part of A is not referenced. On exit, the
lower triangular part of 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.
-
* LDA (input)
-
On entry, LDA specifies the first dimension of A as declared
in the calling (sub) program. LDA >= max( 1, n ).
Unchanged on exit.