SLATEC Routines --- PRWVIR ---

*DECK PRWVIR
      SUBROUTINE PRWVIR (KEY, IPAGE, LPG, SX, IX)
C***BEGIN PROLOGUE  PRWVIR
C***SUBSIDIARY
C***PURPOSE  Subsidiary to SPLP
C***LIBRARY   SLATEC
C***TYPE      SINGLE PRECISION (PRWVIR-S, DPRWVR-D)
C***AUTHOR  Hanson, R. J., (SNLA)
C           Wisniewski, J. A., (SNLA)
C***DESCRIPTION
C
C     PRWVIR LIMITS THE TYPE OF STORAGE TO A SEQUENTIAL SPARSE MATRIX
C     STORAGE SCHEME.  THE PAGE STORAGE IS ON RANDOM ACCESS DISK.
C     PRWVIR IS PART OF THE SPARSE LP PACKAGE, SPLP.
C
C     KEY       IS A FLAG WHICH INDICATES WHETHER A READ OR WRITE
C               OPERATION IS TO BE PERFORMED. A VALUE OF KEY=1 INDICATES
C               A READ. A VALUE OF KEY=2 INDICATES A WRITE.
C     IPAGE     IS THE PAGE OF MATRIX MN WE ARE ACCESSING.
C     LPG       IS THE LENGTH OF THE PAGE.
C   SX(*),IX(*) IS THE MATRIX DATA.
C
C     THIS SUBROUTINE IS A MODIFICATION OF THE SUBROUTINE LRWVIR,
C     SANDIA LABS. REPT. SAND78-0785.
C     MODIFICATIONS BY K.L. HIEBERT AND R.J. HANSON
C
C***SEE ALSO  SPLP
C***ROUTINES CALLED  SOPENM, SREADP, SWRITP
C***REVISION HISTORY  (YYMMDD)
C   811215  DATE WRITTEN
C   891009  Removed unreferenced variables.  (WRB)
C   891214  Prologue converted to Version 4.0 format.  (BAB)
C   900328  Added TYPE section.  (WRB)
C   910403  Updated AUTHOR and DESCRIPTION sections.  (WRB)
C***END PROLOGUE  PRWVIR