org.netlib.blas
Class DSBMV
java.lang.Object
org.netlib.blas.DSBMV
public class DSBMV
 extends java.lang.Object
DSBMV is a simplified interface to the JLAPACK routine dsbmv.
This interface converts Javastyle 2D rowmajor arrays into
the 1D columnmajor 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
* =======
*
* DSBMV performs the matrixvector 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 band matrix, with k superdiagonals.
*
* Parameters
* ==========
*
* UPLO  CHARACTER*1.
* On entry, UPLO specifies whether the upper or lower
* triangular part of the band matrix A is being supplied as
* follows:
*
* UPLO = 'U' or 'u' The upper triangular part of A is
* being supplied.
*
* UPLO = 'L' or 'l' The lower triangular part of A is
* being supplied.
*
* Unchanged on exit.
*
* N  INTEGER.
* On entry, N specifies the order of the matrix A.
* N must be at least zero.
* Unchanged on exit.
*
* K  INTEGER.
* On entry, K specifies the number of superdiagonals of the
* matrix A. K must satisfy 0 .le. K.
* 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 with UPLO = 'U' or 'u', the leading ( k + 1 )
* by n part of the array A must contain the upper triangular
* band part of the symmetric matrix, supplied column by
* column, with the leading diagonal of the matrix in row
* ( k + 1 ) of the array, the first superdiagonal starting at
* position 2 in row k, and so on. The top left k by k triangle
* of the array A is not referenced.
* The following program segment will transfer the upper
* triangular part of a symmetric band matrix from conventional
* full matrix storage to band storage:
*
* DO 20, J = 1, N
* M = K + 1  J
* DO 10, I = MAX( 1, J  K ), J
* A( M + I, J ) = matrix( I, J )
* 10 CONTINUE
* 20 CONTINUE
*
* Before entry with UPLO = 'L' or 'l', the leading ( k + 1 )
* by n part of the array A must contain the lower triangular
* band part of the symmetric matrix, supplied column by
* column, with the leading diagonal of the matrix in row 1 of
* the array, the first subdiagonal starting at position 1 in
* row 2, and so on. The bottom right k by k triangle of the
* array A is not referenced.
* The following program segment will transfer the lower
* triangular part of a symmetric band matrix from conventional
* full matrix storage to band storage:
*
* DO 20, J = 1, N
* M = 1  J
* DO 10, I = J, MIN( N, J + K )
* A( M + I, J ) = matrix( I, J )
* 10 CONTINUE
* 20 CONTINUE
*
* 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
* ( k + 1 ).
* 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
* 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.
* 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
* 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 22October1986.
* Jack Dongarra, Argonne National Lab.
* Jeremy Du Croz, Nag Central Office.
* Sven Hammarling, Nag Central Office.
* Richard Hanson, Sandia National Labs.
*
*
* .. Parameters ..
Constructor Summary 
DSBMV()

Method Summary 
static void 
DSBMV(java.lang.String uplo,
int n,
int k,
double alpha,
double[][] a,
double[] x,
int incx,
double beta,
double[] y,
int incy)

Methods inherited from class java.lang.Object 
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait 
DSBMV
public DSBMV()
DSBMV
public static void DSBMV(java.lang.String uplo,
int n,
int k,
double alpha,
double[][] a,
double[] x,
int incx,
double beta,
double[] y,
int incy)