In order for this example to work, you need to put the path to the chimp python
module in your PYTHONPATH variable (or into the sys.path list at runtime).
Set PYTHONPATH like:
 >>export PYTHONPATH=/path/to/chimp/python:$PYTHONPATH


You will also need the python component of the physical package to be in your
PYTHONPATH variable.  The physical package can be downloaded from:
  http://github.com/hpcdev/physical
    or
  http://github.com/olsonse/physical

and then set PYTHONPATH like:
 >>export PYTHONPATH=/path/to/physical/python:$PYTHONPATH


If the chimp python package is not in an immediate subdirectory of the CHIMP
package, you need to (in your python script):
 >>import chimp
 >>chimp.config.CHIMP_DATA = '/path/to/chimp/data/particledb.xml'

 where the CHIMP_DATA path must point to a file that includes particle name and
 mass information per the CHIMP data spec.


 Then you can run the examples.