DORGHR man page on RedHat

Man page or keyword search:  
man Server   29550 pages
apropos Keyword Search (all sections)
Output format
RedHat logo
[printable version]

dorghr.f(3)			    LAPACK			   dorghr.f(3)

NAME
       dorghr.f -

SYNOPSIS
   Functions/Subroutines
       subroutine dorghr (N, ILO, IHI, A, LDA, TAU, WORK, LWORK, INFO)
	   DORGHR

Function/Subroutine Documentation
   subroutine dorghr (integerN, integerILO, integerIHI, double precision,
       dimension( lda, * )A, integerLDA, double precision, dimension( * )TAU,
       double precision, dimension( * )WORK, integerLWORK, integerINFO)
       DORGHR

       Purpose:

	    DORGHR generates a real orthogonal matrix Q which is defined as the
	    product of IHI-ILO elementary reflectors of order N, as returned by
	    DGEHRD:

	    Q = H(ilo) H(ilo+1) . . . H(ihi-1).

       Parameters:
	   N

		     N is INTEGER
		     The order of the matrix Q. N >= 0.

	   ILO

		     ILO is INTEGER

	   IHI

		     IHI is INTEGER

		     ILO and IHI must have the same values as in the previous call
		     of DGEHRD. Q is equal to the unit matrix except in the
		     submatrix Q(ilo+1:ihi,ilo+1:ihi).
		     1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.

	   A

		     A is DOUBLE PRECISION array, dimension (LDA,N)
		     On entry, the vectors which define the elementary reflectors,
		     as returned by DGEHRD.
		     On exit, the N-by-N orthogonal matrix Q.

	   LDA

		     LDA is INTEGER
		     The leading dimension of the array A. LDA >= max(1,N).

	   TAU

		     TAU is DOUBLE PRECISION array, dimension (N-1)
		     TAU(i) must contain the scalar factor of the elementary
		     reflector H(i), as returned by DGEHRD.

	   WORK

		     WORK is DOUBLE PRECISION array, dimension (MAX(1,LWORK))
		     On exit, if INFO = 0, WORK(1) returns the optimal LWORK.

	   LWORK

		     LWORK is INTEGER
		     The dimension of the array WORK. LWORK >= IHI-ILO.
		     For optimum performance LWORK >= (IHI-ILO)*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

		     INFO is INTEGER
		     = 0:  successful exit
		     < 0:  if INFO = -i, the i-th argument had an illegal value

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   November 2011

       Definition at line 127 of file dorghr.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2			Tue Sep 25 2012			   dorghr.f(3)
[top]

List of man pages available for RedHat

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net