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Class org.netlib.blas.DGEMV

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

public class DGEMV

extends Object

DGEMV is a simplified interface to the JLAPACK routine dgemv.
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
 *  =======
 *
 *  DGEMV  performs one of the matrix-vector operations
 *
 *     y := alpha*A*x + beta*y,   or   y := alpha*A'*x + beta*y,
 *
 *  where alpha and beta are scalars, x and y are vectors and A is an
 *  m by n matrix.
 *
 *  Parameters
 *  ==========
 *
 *  TRANS  - CHARACTER*1.
 *           On entry, TRANS specifies the operation to be performed as
 *           follows:
 *
 *              TRANS = 'N' or 'n'   y := alpha*A*x + beta*y.
 *
 *              TRANS = 'T' or 't'   y := alpha*A'*x + beta*y.
 *
 *              TRANS = 'C' or 'c'   y := alpha*A'*x + beta*y.
 *
 *           Unchanged on exit.
 *
 *  M      - INTEGER.
 *           On entry, M specifies the number of rows of the matrix A.
 *           M must be at least zero.
 *           Unchanged on exit.
 *
 *  N      - INTEGER.
 *           On entry, N specifies the number of columns 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.
 *
 *  A      - DOUBLE PRECISION array of DIMENSION ( LDA, n ).
 *           Before entry, the leading m by n part of the array A must
 *           contain the matrix of coefficients.
 *           Unchanged on exit.
 *
 *  LDA    - INTEGER.
 *           On entry, LDA specifies the first dimension of A as declared
 *           in the calling (sub) program. LDA must be at least
 *           max( 1, m ).
 *           Unchanged on exit.
 *
 *  X      - DOUBLE PRECISION array of DIMENSION at least
 *           ( 1 + ( n - 1 )*abs( INCX ) ) when TRANS = 'N' or 'n'
 *           and at least
 *           ( 1 + ( m - 1 )*abs( INCX ) ) otherwise.
 *           Before entry, the incremented array X must contain the
 *           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 + ( m - 1 )*abs( INCY ) ) when TRANS = 'N' or 'n'
 *           and at least
 *           ( 1 + ( n - 1 )*abs( INCY ) ) otherwise.
 *           Before entry with BETA non-zero, the incremented array Y
 *           must contain the 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 ..

DGEMV()

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

 public DGEMV()

 public static void DGEMV(String trans,
                          int m,
                          int n,
                          double alpha,
                          double a[][],
                          double x[],
                          int incx,
                          double beta,
                          double y[],
                          int incy)

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