SLATEC Routines --- POISD2 ---

*DECK POISD2
      SUBROUTINE POISD2 (MR, NR, ISTAG, BA, BB, BC, Q, IDIMQ, B, W, D,
     +   TCOS, P)
C***BEGIN PROLOGUE  POISD2
C***SUBSIDIARY
C***PURPOSE  Subsidiary to GENBUN
C***LIBRARY   SLATEC
C***TYPE      SINGLE PRECISION (POISD2-S, CMPOSD-C)
C***AUTHOR  (UNKNOWN)
C***DESCRIPTION
C
C     Subroutine to solve Poisson's equation for Dirichlet boundary
C     conditions.
C
C     ISTAG = 1 if the last diagonal block is the matrix A.
C     ISTAG = 2 if the last diagonal block is the matrix A+I.
C
C***SEE ALSO  GENBUN
C***ROUTINES CALLED  COSGEN, S1MERG, TRIX
C***REVISION HISTORY  (YYMMDD)
C   801001  DATE WRITTEN
C   890531  Changed all specific intrinsics to generic.  (WRB)
C   891214  Prologue converted to Version 4.0 format.  (BAB)
C   900402  Added TYPE section.  (WRB)
C   920130  Modified to use merge routine S1MERG rather than deleted
C           routine MERGE.  (WRB)
C***END PROLOGUE  POISD2