org.netlib.lapack
Class Dorgbr

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

public class Dorgbr
extends java.lang.Object

Following is the description from the original
Fortran source.  For each array argument, the Java
version will include an integer offset parameter, so
the arguments may not match the description exactly.
Contact seymour@cs.utk.edu with any questions.

* .. * * Purpose * ======= * * DORGBR generates one of the real orthogonal matrices Q or P**T * determined by DGEBRD when reducing a real matrix A to bidiagonal * form: A = Q * B * P**T. Q and P**T are defined as products of * elementary reflectors H(i) or G(i) respectively. * * If VECT = 'Q', A is assumed to have been an M-by-K matrix, and Q * is of order M: * if m >= k, Q = H(1) H(2) . . . H(k) and DORGBR returns the first n * columns of Q, where m >= n >= k; * if m < k, Q = H(1) H(2) . . . H(m-1) and DORGBR returns Q as an * M-by-M matrix. * * If VECT = 'P', A is assumed to have been a K-by-N matrix, and P**T * is of order N: * if k < n, P**T = G(k) . . . G(2) G(1) and DORGBR returns the first m * rows of P**T, where n >= m >= k; * if k >= n, P**T = G(n-1) . . . G(2) G(1) and DORGBR returns P**T as * an N-by-N matrix. * * Arguments * ========= * * VECT (input) CHARACTER*1 * Specifies whether the matrix Q or the matrix P**T is * required, as defined in the transformation applied by DGEBRD: * = 'Q': generate Q; * = 'P': generate P**T. * * M (input) INTEGER * The number of rows of the matrix Q or P**T to be returned. * M >= 0. * * N (input) INTEGER * The number of columns of the matrix Q or P**T to be returned. * N >= 0. * If VECT = 'Q', M >= N >= min(M,K); * if VECT = 'P', N >= M >= min(N,K). * * K (input) INTEGER * If VECT = 'Q', the number of columns in the original M-by-K * matrix reduced by DGEBRD. * If VECT = 'P', the number of rows in the original K-by-N * matrix reduced by DGEBRD. * K >= 0. * * A (input/output) DOUBLE PRECISION array, dimension (LDA,N) * On entry, the vectors which define the elementary reflectors, * as returned by DGEBRD. * On exit, the M-by-N matrix Q or P**T. * * LDA (input) INTEGER * The leading dimension of the array A. LDA >= max(1,M). * * TAU (input) DOUBLE PRECISION array, dimension * (min(M,K)) if VECT = 'Q' * (min(N,K)) if VECT = 'P' * TAU(i) must contain the scalar factor of the elementary * reflector H(i) or G(i), which determines Q or P**T, as * returned by DGEBRD in its array argument TAUQ or TAUP. * * 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,min(M,N)). * For optimum performance LWORK >= min(M,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 had an illegal value * * ===================================================================== * * .. Parameters ..


Constructor Summary
Dorgbr()
           
 
Method Summary
static void dorgbr(java.lang.String vect, int m, int n, int k, double[] a, int _a_offset, int lda, double[] tau, int _tau_offset, double[] work, int _work_offset, int lwork, intW info)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Dorgbr

public Dorgbr()
Method Detail

dorgbr

public static void dorgbr(java.lang.String vect,
                          int m,
                          int n,
                          int k,
                          double[] a,
                          int _a_offset,
                          int lda,
                          double[] tau,
                          int _tau_offset,
                          double[] work,
                          int _work_offset,
                          int lwork,
                          intW info)