dohtrl.f
SUBROUTINE DOHTRL (Q, N, NRDA, DIAG, IRANK, DIV, TD)
C***BEGIN PROLOGUE DOHTRL
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Warning: this routine is not intended to be user-callable.
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C***SUBSIDIARY
C***PURPOSE Subsidiary to DBVSUP and DSUDS
C***LIBRARY SLATEC
C***TYPE DOUBLE PRECISION (OHTROL-S, DOHTRL-D)
C***AUTHOR Watts, H. A., (SNLA)
C***DESCRIPTION
C
C For a rank deficient problem, additional orthogonal
C HOUSEHOLDER transformations are applied to the left side
C of Q to further reduce the triangular form.
C Thus, after application of the routines DORTHR and DOHTRL
C to the original matrix, the result is a nonsingular
C triangular matrix while the remainder of the matrix
C has been zeroed out.
C
C***SEE ALSO DBVSUP, DSUDS
C***ROUTINES CALLED DDOT
C***REVISION HISTORY (YYMMDD)
C 750601 DATE WRITTEN
C 890531 Changed all specific intrinsics to generic. (WRB)
C 890831 Modified array declarations. (WRB)
C 891214 Prologue converted to Version 4.0 format. (BAB)
C 900328 Added TYPE section. (WRB)
C 910722 Updated AUTHOR section. (ALS)
C***END PROLOGUE DOHTRL