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JPLEPHTEST

JPLEPHTEST

Name


  JPLEPHTEST

Author


  Craig B. Markwardt, NASA/GSFC Code 662, Greenbelt, MD 20770
  craigm@lheamail.gsfc.nasa.gov
  UPDATED VERSIONs can be found on my WEB PAGE:
      http://cow.physics.wisc.edu/~craigm/idl/idl.html

Purpose


  Test JPLEPHTEST with JPL test data set

Major Topics


  Planetary Orbits, Interpolation

Calling Sequence


  JPLEPHTEST, EPHFILE, TESTFILE

Description



  JPLEPHTEST tests the JPLEPHINTERP procedure for precision. In
  order to function, you must have a JPL ephemeris test data set.
  The test data set testpo.405 is available in
  ftp://idlastro.gsfc.nasa.gov/pub/data
  The procedure opens and reads the test set, which contains
  precomputed data. Every tenth value is printed on the screen.
  Any deviations that exceed 1.5d-13 AU = 1.5 cm are reported.
  The columns are labelled according to the input file, except for
  the final column, which is the deviation between the input file
  and the computed value.

Parameters



  EPHFILE - a scalar string, specifies the name of the ephemeris
            file, in FITS format. JPLEPHTEST will look in the directory
            $ASTRO_DATA for the file if it is not in the current directory.
  TESTFILE - a scalar string, specifies JPL test data set to compare
              against. JPLEPHTEST will look in the directory
            $ASTRO_DATA for the file if it is not in the current directory.

Example



  Test JPL DE200 and DE405 ephemerides. Assumes files are in the
  current directory.
  JPLEPHTEST, 'JPLEPH.200', 'testpo.200'
  JPLEPHTEST, 'JPLEPH.405', 'testpo.405'
   

References



  JPL Export Ephemeris FTP Site
      ftp://ssd.jpl.nasa.gov/pub/eph/planets/
      (see test-data/ for test data sets)
 
  HORIZONS, JPL Web-based ephermis calculator (Ephemeris DE406)
      http://ssd.jpl.nasa.gov/horizons.html

See Also


  JPLEPHREAD, JPLEPHINTERP, JPLEPHTEST
 

Modification History


  Written and Documented, CM, Jun 2001
  Removed TRANSREAD, improved output, improved docs, CM, 9 Jul 2001
  $Id: jplephtest.pro,v 1.4 2001/07/20 13:29:53 craigm Exp $



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