sla_syamv (3p)

Name

sla_syamv - nite matrix to calculate error bounds

Synopsis

SUBROUTINE SLA_SYAMV(UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)


REAL ALPHA, BETA

INTEGER INCX, INCY, LDA, N, UPLO

REAL A(LDA,*), X(*), Y(*)


SUBROUTINE SLA_SYAMV_64(UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)


REAL ALPHA, BETA

INTEGER*8 INCX, INCY, LDA, N, UPLO

REAL A(LDA,*), X(*), Y(*)


F95 INTERFACE
SUBROUTINE LA_SYAMV(UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)


REAL, DIMENSION(:,:) :: A

INTEGER :: UPLO, N, LDA, INCX, INCY

REAL, DIMENSION(:) :: X, Y

REAL :: ALPHA, BETA


SUBROUTINE LA_SYAMV_64(UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)


REAL, DIMENSION(:,:) :: A

INTEGER(8) :: UPLO, N, LDA, INCX, INCY

REAL, DIMENSION(:) :: X, Y

REAL :: ALPHA, BETA


C INTERFACE
#include <sunperf.h>

void  sla_syamv (int uplo, int n, float alpha, float *a, int lda, float
*x, int incx, float beta, float *y, int incy);


void sla_syamv_64 (long uplo, long n, float alpha, float *a, long  lda,
float *x, long incx, float beta, float *y, long incy);

Description

Oracle Solaris Studio Performance Library                        sla_syamv(3P)



NAME
       sla_syamv  -  compute a matrix-vector product using a symmetric indefi-
       nite matrix to calculate error bounds


SYNOPSIS
       SUBROUTINE SLA_SYAMV(UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)


       REAL ALPHA, BETA

       INTEGER INCX, INCY, LDA, N, UPLO

       REAL A(LDA,*), X(*), Y(*)


       SUBROUTINE SLA_SYAMV_64(UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)


       REAL ALPHA, BETA

       INTEGER*8 INCX, INCY, LDA, N, UPLO

       REAL A(LDA,*), X(*), Y(*)


   F95 INTERFACE
       SUBROUTINE LA_SYAMV(UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)


       REAL, DIMENSION(:,:) :: A

       INTEGER :: UPLO, N, LDA, INCX, INCY

       REAL, DIMENSION(:) :: X, Y

       REAL :: ALPHA, BETA


       SUBROUTINE LA_SYAMV_64(UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)


       REAL, DIMENSION(:,:) :: A

       INTEGER(8) :: UPLO, N, LDA, INCX, INCY

       REAL, DIMENSION(:) :: X, Y

       REAL :: ALPHA, BETA


   C INTERFACE
       #include <sunperf.h>

       void  sla_syamv (int uplo, int n, float alpha, float *a, int lda, float
                 *x, int incx, float beta, float *y, int incy);


       void sla_syamv_64 (long uplo, long n, float alpha, float *a, long  lda,
                 float *x, long incx, float beta, float *y, long incy);


PURPOSE
       sla_syamv  performs the matrix-vector operation

       y := alpha*abs(A)*abs(x) + beta*abs(y),

       where  alpha and beta are scalars, x and y are vectors and A is an n by
       n symmetric matrix.

       This function is primarily used in calculating error bounds.   To  pro-
       tect  against  underflow during evaluation, components in the resulting
       vector are perturbed away  from  zero  by  (N+1)  times  the  underflow
       threshold.   To  prevent unnecessarily large errors for block-structure
       embedded in general matrices, "symbolically" zero  components  are  not
       perturbed.   A  zero  entry is considered "symbolic" if all multiplica-
       tions involved in computing that entry have at least one zero multipli-
       cand.


ARGUMENTS
       UPLO (input)
                 UPLO is INTEGER
                 On  entry, UPLO specifies whether the upper or lower triangu-
                 lar part of the array A is to be referenced as follows:
                 UPLO = BLAS_UPPER   Only the upper triangular part of A is to
                 be referenced.
                 UPLO = BLAS_LOWER   Only the lower triangular part of A is to
                 be referenced.
                 Unchanged on exit.


       N (input)
                 N is INTEGER
                 On entry, N specifies the number of columns of the matrix  A.
                 N must be at least zero.
                 Unchanged on exit.


       ALPHA (input)
                 ALPHA is REAL
                 On entry, ALPHA specifies the scalar alpha.
                 Unchanged on exit.


       A (input)
                 A is REAL array of DIMENSION ( LDA, n )
                 Before  entry,  the  leading  m by n part of the array A must
                 contain the matrix of coefficients.
                 Unchanged on exit.


       LDA (input)
                 LDA is INTEGER
                 On entry, LDA specifies the first dimension of A as  declared
                 in  the calling (sub) program. LDA must be at least max( 1, n
                 ).
                 Unchanged on exit.


       X (input)
                 X is REAL array, dimension
                 ( 1 + ( n - 1 )*abs( INCX ) )
                 Before entry, the incremented array X must contain the vector
                 x.
                 Unchanged on exit.


       INCX (input)
                 INCX is INTEGER
                 On entry, INCX specifies the increment for the elements of X.
                 INCX must not be zero.
                 Unchanged on exit.


       BETA (input)
                 BETA is REAL
                 On entry, BETA specifies the scalar beta. When BETA  is  sup-
                 plied  as zero then Y need not be set on input.  Unchanged on
                 exit.


       Y (input/output)
                 Y is REAL array, dimension
                 ( 1 + ( n - 1 )*abs( INCY ) )
                 Before entry with BETA non-zero, the incremented array Y must
                 contain  the  vector  y.  On  exit,  Y  is overwritten by the
                 updated vector y.


       INCY (input)
                 INCY is INTEGER
                 On entry, INCY specifies the increment for the elements of Y.
                 INCY must not be zero.
                 Unchanged on exit.




                                  7 Nov 2015                     sla_syamv(3P)