org.netlib.blas
Class Dgemv

java.lang.Object
  org.netlib.blas.Dgemv

public class Dgemv
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
 *  =======
 *
 *  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 ..

Constructor Summary

Dgemv()

Method Summary

static void

dgemv(java.lang.String trans, int m, int n, double alpha, double[] a, int _a_offset, int lda, double[] x, int _x_offset, int incx, double beta, double[] y, int _y_offset, int incy)

Methods inherited from class java.lang.Object

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

Constructor Detail

Dgemv

public Dgemv()

Method Detail

dgemv

public static void dgemv(java.lang.String trans,
                         int m,
                         int n,
                         double alpha,
                         double[] a,
                         int _a_offset,
                         int lda,
                         double[] x,
                         int _x_offset,
                         int incx,
                         double beta,
                         double[] y,
                         int _y_offset,
                         int incy)