[MMTK] how to deal with the error "TypeError: a float is required"

[jak at biogeo.uw.edu.pl]

Hi,

I recived your traceback and script. It seems that the problem is that
"0.8" is a string rather than a number, thus:

  universe = InfiniteUniverse(Amber94ForceField(None,"0.8"))

should be replaced with:

  universe = InfiniteUniverse(Amber94ForceField(None,0.8))

Note however, that this will give you "cutoff" method and not Ewald
summation which is available only for periodic universes.
If you had periodic universe than in order to get Ewald summation you
would have to pass dictionary for the electrostatic option, for example:

  Amber94ForceField(None, {"method": "ewald"})

Description of Amber94ForceField is here:
http://starship.python.net/crew/hinsen/MMTK/Manual/MMTK_20.html

Best wishes,

Jaroslaw Kalinowski