org.netlib.blas
Class Dspr2

java.lang.Object
  org.netlib.blas.Dspr2

public class Dspr2
extends java.lang.Object

Following is the description from the original
Fortran source.  For each array argument, the Java
version will include an integer offset parameter, so
the arguments may not match the description exactly.
Contact seymour@cs.utk.edu with any questions.


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

Constructor Summary

Dspr2()

Method Summary

static void

dspr2(java.lang.String uplo, int n, double alpha, double[] x, int _x_offset, int incx, double[] y, int _y_offset, int incy, double[] ap, int _ap_offset)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Dspr2

public Dspr2()

Method Detail

dspr2

public static void dspr2(java.lang.String uplo,
                         int n,
                         double alpha,
                         double[] x,
                         int _x_offset,
                         int incx,
                         double[] y,
                         int _y_offset,
                         int incy,
                         double[] ap,
                         int _ap_offset)