Simulation of Particles Dynamics in Clojure
===========================================

Object
------

This command line application calculates  the trajectories of a set of
material  points  (particles).  The intial  conditions  like  postion,
velocity and masses as well  as fundamental simulation parameters like
error bounds, number of steps, etc. have to be defined in advance. The
program  will  then calculate  the  movement  of each  particle  using
Runge-Kutta 4/5  order integration  with automatic step  size control.
Due to the functional programming style the computational load will be
distributed  over  the  available  CPU cores  which  can  dramatically
increase processing speed in some cases.

Build
-----

You need  the clojure build  tool leinignen for  compilation. Download
the lein script file from Github

cd ~/bin
wget http://github.com/technomancy/leiningen/raw/stable/bin/lein
chmod +x lein

and type

lein self-install

The following commands will generate and stand-alone jar file:

lein compile
lein uberjar

Refer also to
http://zef.me/2470/building-clojure-projects-with-leiningen
for more specific information about build options.


Invocation
----------

The following  command will simulate  our solar system  planet trajec-
tories:

java -jar particles-0.1-standalone.jar data/solar.prm data/solar.ini \
  data/solar.trj 


Output File Format
------------------

The  trajectory file  itself comes  in GNU-plot  format. To  visualize
start  GNU-plot  and  enter   the  command  <load  "trajectory-file">.
Alternatively  dedicated trajectory  viewer application  are available
for the Java plattform and Mac OS X.

-------------------------
June 2011, Otto Linnemann