Getting Started

Documentation

Glish

Learn More

Programming

Contact Us

Version 1.9 Build 1488

News	FAQ
Search	Home

measures.direction - Function

	Package	general
	Module	measures
	Tool	measures

define a direction measure

Synopsis
direction(rf, v0, v1, off)

Arguments

rf	in	reference code
		Allowed:	coded string
v0	in	longitude
		Allowed:	quantity
		Default:	0..
v1	in	latitude
		Allowed:	quantity
		Default:	90..
off	in	optional offset
		Allowed:	direction measure
		Default:	F

Returns
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 when a vector of quantities is given), 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 Glish with:

- dm.listcodes(dm.direction())
[normal=J2000 JMEAN JTRUE APP B1950 BMEAN BTRUE GALACTIC HADEC AZEL
        AZELSW AZELNE AZELGEO AZELSWGEO AZELNEGEO JNAT ECLIPTIC
        MECLIPTIC TECLIPTIC SUPERGAL ITRF TOPO,
 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.

Example

- dm.direction('j2000','30deg','40deg')
[type=direction, refer=j2000, m0=[value=0.523599, unit=rad], 
	m1=[value=0.698132, unit=rad]]
- dm.direction('mars')
[type=direction, refer=mars, m0=[value=0, unit=rad], 
	m1=[value=1.57079633, unit=rad]]