1.3.1.0 measures.direction

1.3.1 define a direction measure
Description

direction defines a direction measure from the CLI. It has to specify a reference code, direction quantity values (see introduction for the action on a scalar quantity with either a vector or scalar value),

and optionally it can specify an offset, which in itself has to be a direction. Allowable reference codes are: J2000 JMEAN JTRUE APP B1950 BMEAN BTRUE GALACTIC HADEC AZEL SUPERGAL ECLIPTIC MECLIPTIC TECLIPTIC MERCURY VENUS MARS JUPITER SATURN URANUS NEPTUNE PLUTO MOON SUN COMET.
Note that additional ones may become available. Check in CASA with:

print "\t----\t direction Ex 1 \t----"
print me.listcodes(me.direction())
#{’normal’: [’J2000’, ’JMEAN’, ’JTRUE’, ’APP’, ’B1950’, ’BMEAN’,
#’BTRUE’, ’GALACTIC’, ’HADEC’, ’AZEL’, ’AZELSW’, ’AZELNE’, ’AZELGEO’,
#’AZELSWGEO’, ’AZELNEGEO’, ’JNAT’, ’ECLIPTIC’, ’MECLIPTIC’,
#’TECLIPTIC’, ’SUPERGAL’, ’ITRF’, ’TOPO’, ’ICRS’], ’extra’: [’MERCURY’,
#’VENUS’, ’MARS’, ’JUPITER’, ’SATURN’, ’URANUS’, ’NEPTUNE’, ’PLUTO’,
#’SUN’, ’MOON’, ’COMET’]}

The direction quantity values should be longitude(angle) and latitude(angle) (none needed for planets: the frame epoch defines coordinates). See quantity for possible angle formats.


Inputs
rf	reference code
	allowed:	string
	Default:	J2000
v0	longitude
	allowed:	any
	Default:	variant
v1	latitude
	allowed:	any
	Default:	variant
off	optional offset direction measure
	allowed:	any
	Default:	record

print "\t----\t direction Ex 2 \t----"
print me.direction(’j2000’,’30deg’,’40deg’)
#{’m0’: {’value’: 0.52359877559829882, ’unit’: ’rad’},
# ’m1’: {’value’: 0.69813170079773168, ’unit’: ’rad’},
# ’refer’: ’J2000’,
# ’type’: ’direction’}
#
print me.direction(’mars’)
#{’m0’: {’value’: 0.0, ’unit’: ’rad’},
# ’m1’: {’value’: 1.5707963267948966, ’unit’: ’rad’},
# ’refer’: ’MARS’,
# ’type’: ’direction’}

measures.direction - Function