some cleanup and docstrings

src/amuse/units/optparse.py

@@ -1,4 +1,7 @@
-
+"""
+Overloaded option parser with unit support.
+Now deprecated, standard argparse can be used instead.
+"""
 
 import optparse
 import textwrap

src/amuse/units/units.py

@@ -50,9 +50,8 @@
 
 # astronomical units
 angstrom = named("angstrom", "angstrom", 1e-10 * m)
-AU = named("astronomical unit", "au", 149597870691.0 * m)
 au = named("astronomical unit", "au", 149597870691.0 * m)
-AUd = named("au per day", "aud", 149597870691.0 * m / day)
+aud = named("au per day", "aud", 149597870691.0 * m / day)
 parsec = named("parsec", "parsec", au / numpy.tan(numpy.pi / (180 * 60 * 60)))
 kpc = named("kilo parsec", "kpc", 10**3 * parsec)
 Mpc = named("mega parsec", "Mpc", 10**6 * parsec)
@@ -61,17 +60,28 @@
 # lightyear = named('light year', 'ly', c*julianyr)
 LSun = named("solar luminosity", "LSun", 3.839e26 * W)
 MSun = named("solar mass", "MSun", 1.98892e30 * kg)
-MJupiter = named("jupiter mass", "MJupiter", 1.8987e27 * kg)
-MEarth = named("earth mass", "MEarth", 5.9722e24 * kg)
 RSun = named("solar radius", "RSun", 6.955e8 * m)
+MJupiter = named("jupiter mass", "MJupiter", 1.8987e27 * kg)
 RJupiter = named("jupiter radius", "RJupiter", 71492.0 * km)
+MEarth = named("earth mass", "MEarth", 5.9722e24 * kg)
 REarth = named("earth radius", "REarth", 6371.0088 * km)  # IUGG mean radius
 kyr = named("kilo year", "kyr", 1000 * yr)
 myr = named("million year", "Myr", 1000000 * yr)
-Myr = myr
 gyr = named("giga (billion) year", "Gyr", 1000000000 * yr)
+
+# alternatives, for compatibility
+AU = au
+AUd = aud
+Myr = myr
 Gyr = gyr
 pc = parsec
+Lsun = LSun
+Msun = MSun
+Rsun = RSun
+Mjupiter = MJupiter
+Rjupiter = RJupiter
+Mearth = MEarth
+Rearth = REarth
 
 # cgs units
 g = named("gram", "g", 1e-3 * kg)