dspr2 man page on Scientific

Man page or keyword search:  
man Server   26626 pages
apropos Keyword Search (all sections)
Output format
Scientific logo
[printable version]

DSPR2(1)			 BLAS routine			      DSPR2(1)

NAME
       DSPR2  -	 performs  the	symmetric rank 2 operation   A := alpha*x*y' +
       alpha*y*x' + A,

SYNOPSIS
       SUBROUTINE DSPR2(UPLO,N,ALPHA,X,INCX,Y,INCY,AP)

	   DOUBLE				       PRECISION ALPHA

	   INTEGER				       INCX,INCY,N

	   CHARACTER				       UPLO

	   DOUBLE				       PRECISION
						       AP(*),X(*),Y(*)

PURPOSE
       DSPR2  performs the symmetric rank 2 operation

       where alpha is a scalar, x and y are n element vectors and A is an n by
       n symmetric matrix, supplied in packed form.

ARGUMENTS
       UPLO   - CHARACTER*1.
	      On entry, UPLO specifies whether the upper or  lower  triangular
	      part  of the matrix A is supplied in the packed array AP as fol‐
	      lows:

	      UPLO = 'U' or 'u'	  The upper triangular part of A  is  supplied
	      in AP.

	      UPLO  =  'L' or 'l'   The lower triangular part of A is supplied
	      in AP.

	      Unchanged on exit.

       N      - INTEGER.
	      On entry, N specifies the order of the matrix A.	N must	be  at
	      least zero.  Unchanged on exit.

       ALPHA  - DOUBLE PRECISION.
	      On entry, ALPHA specifies the scalar alpha.  Unchanged on exit.

       X      - DOUBLE PRECISION array of dimension at least
	      (	 1  +  ( n - 1 )*abs( INCX ) ).	 Before entry, the incremented
	      array X must contain the n element vector x.  Unchanged on exit.

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

       Y      - DOUBLE PRECISION array of dimension at least
	      (	 1  +  ( n - 1 )*abs( INCY ) ).	 Before entry, the incremented
	      array Y must contain the n element vector y.  Unchanged on exit.

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

       AP     - DOUBLE PRECISION array of DIMENSION at least
	      (	 (  n*(	 n + 1 ) )/2 ).	 Before entry with  UPLO = 'U' or 'u',
	      the array AP must contain the upper triangular part of the  sym‐
	      metric matrix packed sequentially, column by column, so that AP(
	      1 ) contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a(  1,  2  )
	      and  a( 2, 2 ) respectively, and so on. On exit, the array AP is
	      overwritten by the upper triangular part of the updated  matrix.
	      Before  entry  with UPLO = 'L' or 'l', the array AP must contain
	      the lower triangular part of the symmetric matrix packed sequen‐
	      tially,  column  by  column, so that AP( 1 ) contains a( 1, 1 ),
	      AP( 2 ) and AP( 3 ) contain a( 2, 1 ) and	 a(  3,	 1  )  respec‐
	      tively,  and  so on. On exit, the array AP is overwritten by the
	      lower triangular part of the updated matrix.

FURTHER DETAILS
       Level 2 Blas routine.

       -- Written on 22-October-1986.
	  Jack Dongarra, Argonne National Lab.
	  Jeremy Du Croz, Nag Central Office.
	  Sven Hammarling, Nag Central Office.
	  Richard Hanson, Sandia National Labs.

BLAS routine			 November 2008			      DSPR2(1)
[top]

List of man pages available for Scientific

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net