centos man page for dlaqtr

dlaqtr.f(3)							      LAPACK							       dlaqtr.f(3)

NAME
       dlaqtr.f -

SYNOPSIS
   Functions/Subroutines
       subroutine dlaqtr (LTRAN, LREAL, N, T, LDT, B, W, SCALE, X, WORK, INFO)
	   DLAQTR solves a real quasi-triangular system of equations, or a complex quasi-triangular system of special form, in real arithmetic.

Function/Subroutine Documentation
   subroutine dlaqtr (logicalLTRAN, logicalLREAL, integerN, double precision, dimension( ldt, * )T, integerLDT, double precision, dimension( * )B,
       double precisionW, double precisionSCALE, double precision, dimension( * )X, double precision, dimension( * )WORK, integerINFO)
       DLAQTR solves a real quasi-triangular system of equations, or a complex quasi-triangular system of special form, in real arithmetic.

       Purpose:

	    DLAQTR solves the real quasi-triangular system

			 op(T)*p = scale*c,		  if LREAL = .TRUE.

	    or the complex quasi-triangular systems

		       op(T + iB)*(p+iq) = scale*(c+id),  if LREAL = .FALSE.

	    in real arithmetic, where T is upper quasi-triangular.
	    If LREAL = .FALSE., then the first diagonal block of T must be
	    1 by 1, B is the specially structured matrix

			   B = [ b(1) b(2) ... b(n) ]
			       [       w	    ]
			       [	   w	    ]
			       [	      .     ]
			       [		 w  ]

	    op(A) = A or A**T, A**T denotes the transpose of
	    matrix A.

	    On input, X = [ c ].  On output, X = [ p ].
			  [ d ] 		 [ q ]

	    This subroutine is designed for the condition number estimation
	    in routine DTRSNA.

       Parameters:
	   LTRAN

		     LTRAN is LOGICAL
		     On entry, LTRAN specifies the option of conjugate transpose:
			= .FALSE.,    op(T+i*B) = T+i*B,
			= .TRUE.,     op(T+i*B) = (T+i*B)**T.

	   LREAL

		     LREAL is LOGICAL
		     On entry, LREAL specifies the input matrix structure:
			= .FALSE.,    the input is complex
			= .TRUE.,     the input is real

	   N

		     N is INTEGER
		     On entry, N specifies the order of T+i*B. N >= 0.

	   T

		     T is DOUBLE PRECISION array, dimension (LDT,N)
		     On entry, T contains a matrix in Schur canonical form.
		     If LREAL = .FALSE., then the first diagonal block of T mu
		     be 1 by 1.

	   LDT

		     LDT is INTEGER
		     The leading dimension of the matrix T. LDT >= max(1,N).

	   B

		     B is DOUBLE PRECISION array, dimension (N)
		     On entry, B contains the elements to form the matrix
		     B as described above.
		     If LREAL = .TRUE., B is not referenced.

	   W

		     W is DOUBLE PRECISION
		     On entry, W is the diagonal element of the matrix B.
		     If LREAL = .TRUE., W is not referenced.

	   SCALE

		     SCALE is DOUBLE PRECISION
		     On exit, SCALE is the scale factor.

	   X

		     X is DOUBLE PRECISION array, dimension (2*N)
		     On entry, X contains the right hand side of the system.
		     On exit, X is overwritten by the solution.

	   WORK

		     WORK is DOUBLE PRECISION array, dimension (N)

	   INFO

		     INFO is INTEGER
		     On exit, INFO is set to
			0: successful exit.
			  1: the some diagonal 1 by 1 block has been perturbed by
			     a small number SMIN to keep nonsingularity.
			  2: the some diagonal 2 by 2 block has been perturbed by
			     a small number in DLALN2 to keep nonsingularity.
		     NOTE: In the interests of speed, this routine does not
			   check the inputs for errors.

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   September 2012

       Definition at line 165 of file dlaqtr.f.

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

Version 3.4.2							  Tue Sep 25 2012						       dlaqtr.f(3)