org.netlib.lapack
Class DORGQL
java.lang.Object
org.netlib.lapack.DORGQL
public class DORGQL
- extends java.lang.Object
DORGQL is a simplified interface to the JLAPACK routine dorgql.
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
* =======
*
* DORGQL generates an M-by-N real matrix Q with orthonormal columns,
* which is defined as the last N columns of a product of K elementary
* reflectors of order M
*
* Q = H(k) . . . H(2) H(1)
*
* as returned by DGEQLF.
*
* 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. M >= N >= 0.
*
* K (input) INTEGER
* The number of elementary reflectors whose product defines the
* matrix Q. N >= K >= 0.
*
* A (input/output) DOUBLE PRECISION array, dimension (LDA,N)
* On entry, the (n-k+i)-th column must contain the vector which
* defines the elementary reflector H(i), for i = 1,2,...,k, as
* returned by DGEQLF in the last k columns 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 DGEQLF.
*
* 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,N).
* For optimum performance LWORK >= N*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 ..
Method Summary |
static void |
DORGQL(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 |
DORGQL
public DORGQL()
DORGQL
public static void DORGQL(int m,
int n,
int k,
double[][] a,
double[] tau,
double[] work,
int lwork,
intW info)