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Class org.netlib.blas.Dspmv

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

public class Dspmv

extends 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
 *  =======
 *
 *  DSPMV  performs the matrix-vector operation
 *
 *     y := alpha*A*x + beta*y,
 *
 *  where alpha and beta are scalars, 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.
 *
 *  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.
 *           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.
 *           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.
 *
 *  BETA   - DOUBLE PRECISION.
 *           On entry, BETA specifies the scalar beta. When BETA is
 *           supplied as zero then Y need not be set on input.
 *           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. On exit, Y is overwritten by the updated
 *           vector y.
 *
 *  INCY   - INTEGER.
 *           On entry, INCY specifies the increment for the elements of
 *           Y. INCY must not be zero.
 *           Unchanged on exit.
 *
 *
 *  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 ..

Dspmv()

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

 public Dspmv()

 public static void dspmv(String uplo,
                          int n,
                          double alpha,
                          double ap[],
                          int _ap_offset,
                          double x[],
                          int _x_offset,
                          int incx,
                          double beta,
                          double y[],
                          int _y_offset,
                          int incy)

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