org.netlib.lapack
Class DGGGLM

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

public class DGGGLM
extends java.lang.Object

DGGGLM is a simplified interface to the JLAPACK routine dggglm.
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 * ======= * * DGGGLM solves a general Gauss-Markov linear model (GLM) problem: * * minimize || y ||_2 subject to d = A*x + B*y * x * * where A is an N-by-M matrix, B is an N-by-P matrix, and d is a * given N-vector. It is assumed that M <= N <= M+P, and * * rank(A) = M and rank( A B ) = N. * * Under these assumptions, the constrained equation is always * consistent, and there is a unique solution x and a minimal 2-norm * solution y, which is obtained using a generalized QR factorization * of the matrices (A, B) given by * * A = Q*(R), B = Q*T*Z. * (0) * * In particular, if matrix B is square nonsingular, then the problem * GLM is equivalent to the following weighted linear least squares * problem * * minimize || inv(B)*(d-A*x) ||_2 * x * * where inv(B) denotes the inverse of B. * * Arguments * ========= * * N (input) INTEGER * The number of rows of the matrices A and B. N >= 0. * * M (input) INTEGER * The number of columns of the matrix A. 0 <= M <= N. * * P (input) INTEGER * The number of columns of the matrix B. P >= N-M. * * A (input/output) DOUBLE PRECISION array, dimension (LDA,M) * On entry, the N-by-M matrix A. * On exit, the upper triangular part of the array A contains * the M-by-M upper triangular matrix R. * * LDA (input) INTEGER * The leading dimension of the array A. LDA >= max(1,N). * * B (input/output) DOUBLE PRECISION array, dimension (LDB,P) * On entry, the N-by-P matrix B. * On exit, if N <= P, the upper triangle of the subarray * B(1:N,P-N+1:P) contains the N-by-N upper triangular matrix T; * if N > P, the elements on and above the (N-P)th subdiagonal * contain the N-by-P upper trapezoidal matrix T. * * LDB (input) INTEGER * The leading dimension of the array B. LDB >= max(1,N). * * D (input/output) DOUBLE PRECISION array, dimension (N) * On entry, D is the left hand side of the GLM equation. * On exit, D is destroyed. * * X (output) DOUBLE PRECISION array, dimension (M) * Y (output) DOUBLE PRECISION array, dimension (P) * On exit, X and Y are the solutions of the GLM problem. * * WORK (workspace/output) DOUBLE PRECISION array, dimension (MAX(1,L * On exit, if INFO = 0, WORK(1) returns the optimal LWORK. * * LWORK (input) INTEGER * The dimension of the array WORK. LWORK >= max(1,N+M+P). * For optimum performance, LWORK >= M+min(N,P)+max(N,P)*NB, * where NB is an upper bound for the optimal blocksizes for * DGEQRF, SGERQF, DORMQR and SORMRQ. * * 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 had an illegal value. * = 1: the upper triangular factor R associated with A in the * generalized QR factorization of the pair (A, B) is * singular, so that rank(A) < M; the least squares * solution could not be computed. * = 2: the bottom (N-M) by (N-M) part of the upper trapezoidal * factor T associated with B in the generalized QR * factorization of the pair (A, B) is singular, so that * rank( A B ) < N; the least squares solution could not * be computed. * * =================================================================== * * .. Parameters ..


Constructor Summary
DGGGLM()
           
 
Method Summary
static void DGGGLM(int n, int m, int p, double[][] a, double[][] b, double[] d, double[] x, double[] y, 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

DGGGLM

public DGGGLM()
Method Detail

DGGGLM

public static void DGGGLM(int n,
                          int m,
                          int p,
                          double[][] a,
                          double[][] b,
                          double[] d,
                          double[] x,
                          double[] y,
                          double[] work,
                          int lwork,
                          intW info)