org.netlib.blas
Class DSYR2K
java.lang.Object
org.netlib.blas.DSYR2K
public class DSYR2K
 extends java.lang.Object
DSYR2K is a simplified interface to the JLAPACK routine dsyr2k.
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
* =======
*
* DSYR2K performs one of the symmetric rank 2k operations
*
* C := alpha*A*B' + alpha*B*A' + beta*C,
*
* or
*
* C := alpha*A'*B + alpha*B'*A + beta*C,
*
* where alpha and beta are scalars, C is an n by n symmetric matrix
* and A and B are n by k matrices in the first case and k by n
* matrices in the second case.
*
* Parameters
* ==========
*
* UPLO  CHARACTER*1.
* On entry, UPLO specifies whether the upper or lower
* triangular part of the array C is to be referenced as
* follows:
*
* UPLO = 'U' or 'u' Only the upper triangular part of C
* is to be referenced.
*
* UPLO = 'L' or 'l' Only the lower triangular part of C
* is to be referenced.
*
* Unchanged on exit.
*
* TRANS  CHARACTER*1.
* On entry, TRANS specifies the operation to be performed as
* follows:
*
* TRANS = 'N' or 'n' C := alpha*A*B' + alpha*B*A' +
* beta*C.
*
* TRANS = 'T' or 't' C := alpha*A'*B + alpha*B'*A +
* beta*C.
*
* TRANS = 'C' or 'c' C := alpha*A'*B + alpha*B'*A +
* beta*C.
*
* Unchanged on exit.
*
* N  INTEGER.
* On entry, N specifies the order of the matrix C. N must be
* at least zero.
* Unchanged on exit.
*
* K  INTEGER.
* On entry with TRANS = 'N' or 'n', K specifies the number
* of columns of the matrices A and B, and on entry with
* TRANS = 'T' or 't' or 'C' or 'c', K specifies the number
* of rows of the matrices A and B. K 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, ka ), where ka is
* k when TRANS = 'N' or 'n', and is n otherwise.
* Before entry with TRANS = 'N' or 'n', the leading n by k
* part of the array A must contain the matrix A, otherwise
* the leading k by n part of the array A must contain the
* matrix A.
* Unchanged on exit.
*
* LDA  INTEGER.
* On entry, LDA specifies the first dimension of A as declared
* in the calling (sub) program. When TRANS = 'N' or 'n'
* then LDA must be at least max( 1, n ), otherwise LDA must
* be at least max( 1, k ).
* Unchanged on exit.
*
* B  DOUBLE PRECISION array of DIMENSION ( LDB, kb ), where kb is
* k when TRANS = 'N' or 'n', and is n otherwise.
* Before entry with TRANS = 'N' or 'n', the leading n by k
* part of the array B must contain the matrix B, otherwise
* the leading k by n part of the array B must contain the
* matrix B.
* Unchanged on exit.
*
* LDB  INTEGER.
* On entry, LDB specifies the first dimension of B as declared
* in the calling (sub) program. When TRANS = 'N' or 'n'
* then LDB must be at least max( 1, n ), otherwise LDB must
* be at least max( 1, k ).
* Unchanged on exit.
*
* BETA  DOUBLE PRECISION.
* On entry, BETA specifies the scalar beta.
* Unchanged on exit.
*
* C  DOUBLE PRECISION array of DIMENSION ( LDC, n ).
* Before entry with UPLO = 'U' or 'u', the leading n by n
* upper triangular part of the array C must contain the upper
* triangular part of the symmetric matrix and the strictly
* lower triangular part of C is not referenced. On exit, the
* upper triangular part of the array C is overwritten by the
* upper triangular part of the updated matrix.
* Before entry with UPLO = 'L' or 'l', the leading n by n
* lower triangular part of the array C must contain the lower
* triangular part of the symmetric matrix and the strictly
* upper triangular part of C is not referenced. On exit, the
* lower triangular part of the array C is overwritten by the
* lower triangular part of the updated matrix.
*
* LDC  INTEGER.
* On entry, LDC specifies the first dimension of C as declared
* in the calling (sub) program. LDC must be at least
* max( 1, n ).
* Unchanged on exit.
*
*
* Level 3 Blas routine.
*
*
*  Written on 8February1989.
* Jack Dongarra, Argonne National Laboratory.
* Iain Duff, AERE Harwell.
* Jeremy Du Croz, Numerical Algorithms Group Ltd.
* Sven Hammarling, Numerical Algorithms Group Ltd.
*
*
* .. External Functions ..
Method Summary 
static void 
DSYR2K(java.lang.String uplo,
java.lang.String trans,
int n,
int k,
double alpha,
double[][] a,
double[][] b,
double beta,
double[][] c)

Methods inherited from class java.lang.Object 
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait 
DSYR2K
public DSYR2K()
DSYR2K
public static void DSYR2K(java.lang.String uplo,
java.lang.String trans,
int n,
int k,
double alpha,
double[][] a,
double[][] b,
double beta,
double[][] c)