Go to main content
Oracle Developer Studio 12.5 Man Pages

Exit Print View

Updated: June 2017
 
 

dsyr (3p)

Name

dsyr - perform the symmetric rank 1 operation A := alpha*x*x' + A

Synopsis

SUBROUTINE DSYR(UPLO, N, ALPHA, X, INCX, A, LDA)

CHARACTER*1 UPLO
INTEGER N, INCX, LDA
DOUBLE PRECISION ALPHA
DOUBLE PRECISION X(*), A(LDA,*)

SUBROUTINE DSYR_64(UPLO, N, ALPHA, X, INCX, A, LDA)

CHARACTER*1 UPLO
INTEGER*8 N, INCX, LDA
DOUBLE PRECISION ALPHA
DOUBLE PRECISION X(*), A(LDA,*)




F95 INTERFACE
SUBROUTINE SYR(UPLO, N, ALPHA, X, INCX, A, LDA)

CHARACTER(LEN=1) :: UPLO
INTEGER :: N, INCX, LDA
REAL(8) :: ALPHA
REAL(8), DIMENSION(:) :: X
REAL(8), DIMENSION(:,:) :: A

SUBROUTINE SYR_64(UPLO, N, ALPHA, X, INCX, A, LDA)

CHARACTER(LEN=1) :: UPLO
INTEGER(8) :: N, INCX, LDA
REAL(8) :: ALPHA
REAL(8), DIMENSION(:) :: X
REAL(8), DIMENSION(:,:) :: A




C INTERFACE
#include <sunperf.h>

void  dsyr(char  uplo, int n, double alpha, double *x, int incx, double
*a, int lda);

void dsyr_64(char uplo, long n, double alpha,  double  *x,  long  incx,
double *a, long lda);

Description

Oracle Solaris Studio Performance Library                             dsyr(3P)



NAME
       dsyr - perform the symmetric rank 1 operation   A := alpha*x*x' + A


SYNOPSIS
       SUBROUTINE DSYR(UPLO, N, ALPHA, X, INCX, A, LDA)

       CHARACTER*1 UPLO
       INTEGER N, INCX, LDA
       DOUBLE PRECISION ALPHA
       DOUBLE PRECISION X(*), A(LDA,*)

       SUBROUTINE DSYR_64(UPLO, N, ALPHA, X, INCX, A, LDA)

       CHARACTER*1 UPLO
       INTEGER*8 N, INCX, LDA
       DOUBLE PRECISION ALPHA
       DOUBLE PRECISION X(*), A(LDA,*)




   F95 INTERFACE
       SUBROUTINE SYR(UPLO, N, ALPHA, X, INCX, A, LDA)

       CHARACTER(LEN=1) :: UPLO
       INTEGER :: N, INCX, LDA
       REAL(8) :: ALPHA
       REAL(8), DIMENSION(:) :: X
       REAL(8), DIMENSION(:,:) :: A

       SUBROUTINE SYR_64(UPLO, N, ALPHA, X, INCX, A, LDA)

       CHARACTER(LEN=1) :: UPLO
       INTEGER(8) :: N, INCX, LDA
       REAL(8) :: ALPHA
       REAL(8), DIMENSION(:) :: X
       REAL(8), DIMENSION(:,:) :: A




   C INTERFACE
       #include <sunperf.h>

       void  dsyr(char  uplo, int n, double alpha, double *x, int incx, double
                 *a, int lda);

       void dsyr_64(char uplo, long n, double alpha,  double  *x,  long  incx,
                 double *a, long lda);



PURPOSE
       dsyr performs the symmetric rank 1 operation A := alpha*x*x' + A, where
       alpha is a real scalar, x is an n element vector and A is  an  n  by  n
       symmetric matrix.


ARGUMENTS
       UPLO (input)
                 On  entry, UPLO specifies whether the upper or lower triangu-
                 lar 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.


       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  symmetric  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  symmetric  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.


       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.




                                  7 Nov 2015                          dsyr(3P)