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Class org.netlib.lapack.DORMTR

java.lang.Object
   |
   +----org.netlib.lapack.DORMTR

public class DORMTR
extends Object
DORMTR is a simplified interface to the JLAPACK routine dormtr.
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 * ======= * * DORMTR overwrites the general real M-by-N matrix C with * * SIDE = 'L' SIDE = 'R' * TRANS = 'N': Q * C C * Q * TRANS = 'T': Q**T * C C * Q**T * * where Q is a real orthogonal matrix of order nq, with nq = m if * SIDE = 'L' and nq = n if SIDE = 'R'. Q is defined as the product of * nq-1 elementary reflectors, as returned by DSYTRD: * * if UPLO = 'U', Q = H(nq-1) . . . H(2) H(1); * * if UPLO = 'L', Q = H(1) H(2) . . . H(nq-1). * * Arguments * ========= * * SIDE (input) CHARACTER*1 * = 'L': apply Q or Q**T from the Left; * = 'R': apply Q or Q**T from the Right. * * UPLO (input) CHARACTER*1 * = 'U': Upper triangle of A contains elementary reflectors * from DSYTRD; * = 'L': Lower triangle of A contains elementary reflectors * from DSYTRD. * * TRANS (input) CHARACTER*1 * = 'N': No transpose, apply Q; * = 'T': Transpose, apply Q**T. * * M (input) INTEGER * The number of rows of the matrix C. M >= 0. * * N (input) INTEGER * The number of columns of the matrix C. N >= 0. * * A (input) DOUBLE PRECISION array, dimension * (LDA,M) if SIDE = 'L' * (LDA,N) if SIDE = 'R' * The vectors which define the elementary reflectors, as * returned by DSYTRD. * * LDA (input) INTEGER * The leading dimension of the array A. * LDA >= max(1,M) if SIDE = 'L'; LDA >= max(1,N) if SIDE = 'R'. * * TAU (input) DOUBLE PRECISION array, dimension * (M-1) if SIDE = 'L' * (N-1) if SIDE = 'R' * TAU(i) must contain the scalar factor of the elementary * reflector H(i), as returned by DSYTRD. * * C (input/output) DOUBLE PRECISION array, dimension (LDC,N) * On entry, the M-by-N matrix C. * On exit, C is overwritten by Q*C or Q**T*C or C*Q**T or C*Q. * * LDC (input) INTEGER * The leading dimension of the array C. LDC >= max(1,M). * * 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. * If SIDE = 'L', LWORK >= max(1,N); * if SIDE = 'R', LWORK >= max(1,M). * For optimum performance LWORK >= N*NB if SIDE = 'L', and * LWORK >= M*NB if SIDE = 'R', where NB is the optimal * blocksize. * * INFO (output) INTEGER * = 0: successful exit * < 0: if INFO = -i, the i-th argument had an illegal value * * ===================================================================== * * .. Local Scalars ..


Constructor Index

 o DORMTR()

Method Index

 o DORMTR(String, String, String, int, int, double[][], double[], double[][], double[], int, intW)

Constructors

 o DORMTR
 public DORMTR()

Methods

 o DORMTR
 public static void DORMTR(String side,
                           String uplo,
                           String trans,
                           int m,
                           int n,
                           double a[][],
                           double tau[],
                           double c[][],
                           double work[],
                           int lwork,
                           intW info)

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