program FIT_VT
     
c  Author:  Glen Cowan
c  Date:    June 2004

c  Program to fit positions and radii of sun and venus at transit.
c  Fitting done with the method of least squares.  The chi^2 minimization
c  is carried out with the MINUIT routines from the CERN program library.


       implicit        NONE

c  local variables

       integer            n_dof

       double precision   chi2

c  variables for MINUIT


       integer            ierr
       integer            ird
       integer            isav
       integer            istat
       integer            ivarbl
       integer            iwr
       integer            npari, nparx

       double precision   arglis (10)
       double precision   fmin, fedm, errdef
       external           FCN

       integer            device_type

c  common block for HBOOK

      integer            hbook_common_size
      parameter          (hbook_common_size = 100000)
      integer            hmemor (hbook_common_size)
      common /pawc/      hmemor
      integer            nwords_kuip
      parameter          (nwords_kuip=20000)


c  begin

      call HLIMIT (hbook_common_size)
      call KUINIT (nwords_kuip)
      device_type = 1
      call HPLINT (device_type)

c  Initialize MINUIT

       ird = 5         ! unit number for input to Minuit (keyboard)
       iwr = 6         ! unit number for output from Minuit (screen)
       isav = 7        ! unit number for use of the SAVE command
       call MNINIT (ird, iwr, isav)

c  Set print level to -1 (no output except SHOW commands)

       arglis(1) = -1.d0
       call MNEXCM (FCN, 'SET PRIN', arglis, 1, ierr, 0)

c  Get input data by calling FCN with iflag=1

       arglis(1) = 1.d0
       call MNEXCM (FCN, 'CALL', arglis, 1, ierr, 0)

c  Minimize chi2 using SIMPLEX and MIGRAD 

       call MNEXCM (FCN, 'SIMPLEX', arglis, 0, ierr, 0)
       call MNEXCM (FCN, 'MIGRAD', arglis, 0, ierr, 0)

c  Compute covariance matrix with HESSE

       call MNEXCM (FCN, 'HESSE', arglis, 0, ierr, 0)

c  Finish up by calling FCN with iflag=3

       arglis(1) = 3.d0
       call MNEXCM (FCN, 'CALL', arglis, 1, ierr, 0)

       call HPLEND

       stop
       END