README

README
by Joe Hahn, jhahn@spacescience.org, updated 4 June 2013.

This collection of codes has several goals. 1. I am a newcomer to Java
and OOP, so one purpose of this exercise is to stretch out some new (and hopefully
not too feeble) programming muscles. 2. Write and make available a code
that solves Kepler's equation numerically in Java. Hopefully others will
find this little code useful, see Orbit.java for a more detailed description of
that solver. 3. I've also written this code in C++ and IDL, and I've benchmarked
all three codes; those other codes are uploaded to my github repositories at
https://github.com/joehahn?tab=repositories . All three codes solve
Kepler's equation for the eccentric anomaly E with errors < 10^(-15) radians
for N=10^7 elliptic orbits that have eccentricities logarithmically
distributed between 10^(-6)<e<0.999999. All three codes are executed on my
6 year old Dell Precision T3400. The C++ code executes in 4.25 seconds while
the Java code runs in 7.51 seconds and IDL takes 8.33 seconds to execute, so
the Java code is 1.8 times slower than the C++ equivalent and the IDL code is
2.0 times slower than C++.