org.netlib.lapack
Class DGEQL2

java.lang.Object
  extended by org.netlib.lapack.DGEQL2

public class DGEQL2
extends java.lang.Object

DGEQL2 is a simplified interface to the JLAPACK routine dgeql2.
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 * ======= * * DGEQL2 computes a QL factorization of a real m by n matrix A: * A = Q * L. * * Arguments * ========= * * M (input) INTEGER * The number of rows of the matrix A. M >= 0. * * N (input) INTEGER * The number of columns of the matrix A. N >= 0. * * A (input/output) DOUBLE PRECISION array, dimension (LDA,N) * On entry, the m by n matrix A. * On exit, if m >= n, the lower triangle of the subarray * A(m-n+1:m,1:n) contains the n by n lower triangular matrix L; * if m <= n, the elements on and below the (n-m)-th * superdiagonal contain the m by n lower trapezoidal matrix L; * the remaining elements, with the array TAU, represent the * orthogonal matrix Q as a product of elementary reflectors * (see Further Details). * * LDA (input) INTEGER * The leading dimension of the array A. LDA >= max(1,M). * * TAU (output) DOUBLE PRECISION array, dimension (min(M,N)) * The scalar factors of the elementary reflectors (see Further * Details). * * WORK (workspace) DOUBLE PRECISION array, dimension (N) * * INFO (output) INTEGER * = 0: successful exit * < 0: if INFO = -i, the i-th argument had an illegal value * * Further Details * =============== * * The matrix Q is represented as a product of elementary reflectors * * Q = H(k) . . . H(2) H(1), where k = min(m,n). * * Each H(i) has the form * * H(i) = I - tau * v * v' * * where tau is a real scalar, and v is a real vector with * v(m-k+i+1:m) = 0 and v(m-k+i) = 1; v(1:m-k+i-1) is stored on exit in * A(1:m-k+i-1,n-k+i), and tau in TAU(i). * * ===================================================================== * * .. Parameters ..


Constructor Summary
DGEQL2()
           
 
Method Summary
static void DGEQL2(int m, int n, double[][] a, double[] tau, double[] work, intW info)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

DGEQL2

public DGEQL2()
Method Detail

DGEQL2

public static void DGEQL2(int m,
                          int n,
                          double[][] a,
                          double[] tau,
                          double[] work,
                          intW info)