SLATEC Routines --- IDLOC ---

*DECK IDLOC
      INTEGER FUNCTION IDLOC (LOC, SX, IX)
C***BEGIN PROLOGUE  IDLOC
C***SUBSIDIARY
C***PURPOSE  Subsidiary to DSPLP
C***LIBRARY   SLATEC
C***TYPE      DOUBLE PRECISION (IPLOC-S, IDLOC-D)
C***KEYWORDS  RELATIVE ADDRESS DETERMINATION FUNCTION, SLATEC
C***AUTHOR  Boland, W. Robert, (LANL)
C           Nicol, Tom, (University of British Columbia)
C***DESCRIPTION
C
C   Given a "virtual" location,  IDLOC returns the relative working
C   address of the vector component stored in SX, IX.  Any necessary
C   page swaps are performed automatically for the user in this
C   function subprogram.
C
C   LOC       is the "virtual" address of the data to be retrieved.
C   SX ,IX    represent the matrix where the data is stored.
C
C***SEE ALSO  DSPLP
C***ROUTINES CALLED  DPRWPG, XERMSG
C***REVISION HISTORY  (YYMMDD)
C   890606  DATE WRITTEN
C   890606  REVISION DATE from Version 3.2
C   891214  Prologue converted to Version 4.0 format.  (BAB)
C   900315  CALLs to XERROR changed to CALLs to XERMSG.  (THJ)
C   910731  Added code to set IDLOC to 0 if LOC is non-positive.  (WRB)
C***END PROLOGUE  IDLOC