SLATEC Routines --- DU12LS ---

*DECK DU12LS
      SUBROUTINE DU12LS (A, MDA, M, N, B, MDB, NB, MODE, KRANK, RNORM,
     +   H, W, IC, IR)
C***BEGIN PROLOGUE  DU12LS
C***SUBSIDIARY
C***PURPOSE  Subsidiary to DLLSIA
C***LIBRARY   SLATEC
C***TYPE      DOUBLE PRECISION (U12LS-S, DU12LS-D)
C***AUTHOR  (UNKNOWN)
C***DESCRIPTION
C
C        Given the Householder QR factorization of A, this
C        subroutine solves the system AX=B. If the system
C        is of reduced rank, this routine returns a solution
C        according to the selected mode.
C
C       Note - If MODE.NE.2, W is never accessed.
C
C***SEE ALSO  DLLSIA
C***ROUTINES CALLED  DAXPY, DDOT, DNRM2, DSWAP
C***REVISION HISTORY  (YYMMDD)
C   810801  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***END PROLOGUE  DU12LS