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componentlist.getrefdirra - Function

	Package	synthesis
	Module	componentmodels
	Tool	componentlist

Get the RA of the reference direction.

Synopsis
getrefdirra(which, unit, precision)

Description
The getrefdirra function returns the right ascension of the reference direction of the component as a formatted string. If the reference frame is something other than J2000 or B1950 the value returned is the latitude or the azimuthal angle.

The unit argument specifies the units for the returned value. It can be any angular unit (eg. 'deg', 'rad', 'arcsec', 'mas') or it can be 'angle' or 'time'. If it is 'angle' then the returned string is formatted in degrees, minutes, seconds ie., '+DDD.MM.SS.sss'. If it is 'angle' then the returned string is formatted in hours, minutes, seconds ie., 'HH:MM:SS.sss'.

The precision argument controls the numerical precision of the returned value. For the angular units it controls how many digits are in the returned string. For the 'angle' unit, precisions of two, four & six control whether the degrees, degrees,minutes or degrees, minutes & seconds are returned. Higher precisions increase the precision of the seconds field. Similarly, for the 'time' unit precisions of two, four & six control whether the hours, hours, minutes or hours, minutes & seconds are returned. All directions are stored internally in double precision.

Arguments

which		An index specifying which component
		Allowed:	An integer between 1 and the list length
		Default:	no default
unit		The angular unit of the returned value.
		Allowed:	Any string containing an angular unit or 'angle' or 'time'
		Default:	deg
precision		The number of digits in the returned string.
		Allowed:	Numbers between 1 and 16 make the most sense
		Default:	6

Returns
A formatted string containing the RA of the reference direction.

Example

      include 'componentlist.g'
      cl := componentlist('crux.cl');
      print 'The first component is at RA: ', cl.getrefdirra(1, 'time'),
            ' Dec: ', cl.getrefdirdec(1, 'angle'), 
            ' (', cl.getrefdirframe(1), ')'

This example prints the following:

    The first component is at RA:  12:26:36  Dec:  -063.05.55  ( J2000 )

which is the direction of the first component.