SLATEC Routines --- DOHTRL ---

*DECK DOHTRL
      SUBROUTINE DOHTRL (Q, N, NRDA, DIAG, IRANK, DIV, TD)
C***BEGIN PROLOGUE  DOHTRL
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