All Packages  Class Hierarchy  This Package  Previous  Next  Index

Class org.netlib.blas.DSPR

java.lang.Object
   |
   +----org.netlib.blas.DSPR

public class DSPR

extends Object

DSPR is a simplified interface to the JLAPACK routine dspr.
This interface converts Java-style 2D row-major arrays into
the 1D column-major linearized arrays expected by the lower
level JLAPACK routines.  Using this interface also allows you
to omit offset and leading dimension arguments.  However, because
of these conversions, these routines will be slower than the low
level ones.  Following is the description from the original Fortran
source.  Contact seymour@cs.utk.edu with any questions.

 *     ..
 *
 *  Purpose
 *  =======
 *
 *  DSPR    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, supplied in packed form.
 *
 *  Parameters
 *  ==========
 *
 *  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 follows:
 *
 *              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.
 *
 *  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 symmetric 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 sequentially, column by column, so that AP( 1 )
 *           contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 2, 1 )
 *           and a( 3, 1 ) respectively, and so on. On exit, the array
 *           AP is overwritten by the lower triangular part of the
 *           updated matrix.
 *
 *
 *  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.
 *
 *
 *     .. Parameters ..

DSPR()

DSPR(String, int, double, double[], int, double[])

 public DSPR()

 public static void DSPR(String uplo,
                         int n,
                         double alpha,
                         double x[],
                         int incx,
                         double ap[])

All Packages  Class Hierarchy  This Package  Previous  Next  Index