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      BLOCK DATA COSANG


C     initialises common blocks used by INICOS, ANGSIZ and related
C     routines

C     Code written by Phillip Helbig, Hamburg Observatory, Sep 1995.


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C     declaration of variables in common blocks


C     the usual cosmological variables

      DOUBLE PRECISION LAMBDA, OMEGA, ETA, K

      COMMON /COSMOL/ LAMBDA, OMEGA, ETA, K

C     internal names for other parameter list variables and internal
C     stuff; see INICOS

      INTEGER ERROR, WMTYPE

      DOUBLE PRECISION ZMAX

      LOGICAL NOTYET, VARETA, DEBUG, MAXZ, BOUNCE

      COMMON /ANGINI/ ZMAX, ERROR, WMTYPE,
     $                NOTYET, VARETA, DEBUG, MAXZ, BOUNCE

C     a CHOICE value < 0 indicates that the dependence of ETA on Z is
C     different in the phases of expansion and contraction in a bounce
C     model.

      INTEGER CHOICE

      COMMON /WHICH/ CHOICE

C     to allow computation in the Eddington model, if desired

      LOGICAL RISK

      COMMON /ARTHUR/ RISK

C     sometimes ANGSIZ could be called with a Z which is smaller than
C     ZMAX but large enough for numerical problems.

      DOUBLE PRECISION ZZREAL

      COMMON /FIX/ ZZREAL

C     save

      SAVE /COSMOL/, /ANGINI/, /WHICH/, /ARTHUR/, /FIX/



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C     compile-time initialisation of common block variables


      DOUBLE PRECISION DUMMY, IDUMMY

C     Could be any values, really, in most cases, since most are set to
C     the values passed to INICOS or to values calculated by INICOS
C     before they are used (all of these but K are returned to the
C     calling routine with other names).  Some strange values, however,
C     might help in troubleshooting, though this original implementation
C     in now way depends on this.  The exceptions are a) NOTYET, which
C     must be initialised to .TRUE.---this value should also make
C     troubleshooting with the other LOGICAL values easier as well---
C     b) CHOICE, which we initialize to 0, mainly to avoid a negative
C     value, which means that the dependence of ETA on Z is different
C     during the expanding and contracting phases of a bounce model
C     (if CHOICE is negative, 4 instead of 2 distances are calculated
C     by BOUNCE---this should only be done if the user specifically
C     requests it, by setting CHOICE to a negative value) and c) RISK,
C     which is initialised to .FALSE.  The user can declare the COMMON
C     block ARTHUR in the calling routine and set RISK to .TRUE., in
C     order to make calculations in the Eddington model.

      PARAMETER (DUMMY=-3.473954D-11, IDUMMY=-2222)

      DATA LAMBDA, OMEGA, ETA, K /4*DUMMY/

      DATA ERROR, WMTYPE, ZMAX /-1, IDUMMY, DUMMY/,
     $     NOTYET, VARETA, DEBUG, MAXZ, BOUNCE /5*.TRUE./

      DATA CHOICE /0/

      DATA RISK /.FALSE./

      DATA ZZREAL /DUMMY/



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      END