The routines CONV_A2H and CONV_H2A convert between ``angle'' and heliocentric coordinates.
The solar B-angle is taken into consideration when converting back and forth. The
algorithm for converting between an angle position and heliocentric is
rather straight forward. There are some problems when the position
selected is off of the limb. In this case, a projection is attempted.
It is possible to get the heliocentric coordinate in a string format
similar to ``N12W23'' by using the /string option. The input
of CONV_H2A can be a string array with a similar format (``N12W23'').
Some sample calls are:
IDL> hel = conv_a2h(ang, date)
IDL> hel = conv_a2h(ang, date, /cmd)
IDL> ang = conv_h2a(hel, date, /cmd)