org.netlib.lapack
Class DORGRQ

java.lang.Object
  org.netlib.lapack.DORGRQ

public class DORGRQ
extends java.lang.Object

DORGRQ is a simplified interface to the JLAPACK routine dorgrq.
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
 *  =======
 *
 *  DORGRQ generates an M-by-N real matrix Q with orthonormal rows,
 *  which is defined as the last M rows of a product of K elementary
 *  reflectors of order N
 *
 *        Q  =  H(1) H(2) . . . H(k)
 *
 *  as returned by DGERQF.
 *
 *  Arguments
 *  =========
 *
 *  M       (input) INTEGER
 *          The number of rows of the matrix Q. M >= 0.
 *
 *  N       (input) INTEGER
 *          The number of columns of the matrix Q. N >= M.
 *
 *  K       (input) INTEGER
 *          The number of elementary reflectors whose product defines the
 *          matrix Q. M >= K >= 0.
 *
 *  A       (input/output) DOUBLE PRECISION array, dimension (LDA,N)
 *          On entry, the (m-k+i)-th row must contain the vector which
 *          defines the elementary reflector H(i), for i = 1,2,...,k, as

 *          returned by DGERQF in the last k rows of its array argument
 *          A.
 *          On exit, the M-by-N matrix Q.
 *
 *  LDA     (input) INTEGER
 *          The first dimension of the array A. LDA >= max(1,M).
 *
 *  TAU     (input) DOUBLE PRECISION array, dimension (K)
 *          TAU(i) must contain the scalar factor of the elementary
 *          reflector H(i), as returned by DGERQF.
 *
 *  WORK    (workspace/output) DOUBLE PRECISION array, dimension (LWORK)

 *          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
 *
 *  LWORK   (input) INTEGER
 *          The dimension of the array WORK. LWORK >= max(1,M).
 *          For optimum performance LWORK >= M*NB, where NB is the
 *          optimal blocksize.
 *
 *          If LWORK = -1, then a workspace query is assumed; the routine
 *          only calculates the optimal size of the WORK array, returns
 *          this value as the first entry of the WORK array, and no error
 *          message related to LWORK is issued by XERBLA.
 *
 *  INFO    (output) INTEGER
 *          = 0:  successful exit
 *          < 0:  if INFO = -i, the i-th argument has an illegal value
 *
 *  =====================================================================
 *
 *     .. Parameters ..

Constructor Summary

DORGRQ()

Method Summary

static void

DORGRQ(int m, int n, int k, double[][] a, double[] tau, double[] work, int lwork, intW info)

Methods inherited from class java.lang.Object

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

Constructor Detail

DORGRQ

public DORGRQ()

Method Detail

DORGRQ

public static void DORGRQ(int m,
                          int n,
                          int k,
                          double[][] a,
                          double[] tau,
                          double[] work,
                          int lwork,
                          intW info)