from __future__ import division # confidence high

# This dictionary maps an instrument into an instrument class
# The instrument class handles instrument specific keywords

inst_mappings={'WFPC2': 'WFPC2WCS',
                'ACS': 'ACSWCS',
                'NICMOS': 'NICMOSWCS',
                'STIS': 'STISWCS',
                'WFC3': 'WFC3WCS',
                'DEFAULT': 'InstrWCS'
                }


# A list of instrument specific keywords
# Every instrument class must have methods which define each of these
# as class attributes.
ins_spec_kw = [ 'idctab', 'offtab', 'date_obs', 'ra_targ', 'dec_targ', 'pav3', \
                'detector', 'ltv1', 'ltv2', 'parity', 'binned','vafactor', \
                'chip', 'naxis1', 'naxis2', 'filter1', 'filter2']

# A list of keywords defined in the primary header.
# The HSTWCS class sets this as attributes 
prim_hdr_kw = ['detector', 'offtab', 'idctab', 'date-obs', 
              'pa_v3', 'ra_targ', 'dec_targ']

# These are the keywords which are archived before MakeWCS is run
basic_wcs = ['CD1_', 'CD2_', 'CRVAL', 'CTYPE', 'CRPIX', 'CTYPE', 'CDELT', 'CUNIT']