pyast-stcs-example.py

#!/usr/bin/env python

import starlink.Ast as Ast

#  Create a text file containing an STC-S phrase.
with open("stcs1","w") as f:
   f.write('''
Union ICRS TOPOCENTER (
   Circle 180 10 20
   Circle 190 10 20
   Intersection (
      Circle 120 -10 20
      Difference (
         Circle 130 -10 20
         Circle 125 -10 2
      )
      Not ( Circle 118 -8 3 )
   )
   Box 165 -30 30 60
)
''')

#  Create a text file containing a second STC-S phrase.
with open("stcs2","w") as f:
   f.write('''
Circle ICRS TOPOCENTER 150 0 5
''')

#  Create an StcsChan - a channel for converting between STC-S phraes and
#  AST Objects.
ch = Ast.StcsChan()
ch.ReportLevel = 3

# Read the first STC-S phrase, creating an AST Region.
ch.SourceFile = "stcs1"
obj1 = ch.read()

# Read the second STC-S phrase, creating another AST Region.
ch.SourceFile = "stcs2"
obj2 = ch.read()

#  Test if the two Regions overlap.
if obj2.overlap(obj1):
  print( "They overlap" )
else:
  print( "They do not overlap" )