Specifying particles per debye (hyper) cube

[sigvaldm]

This would be cool. Allows us to experiment with keeping the number of particles per debye cube constant while changing other parameters, in case that is what it takes to keep accuracy good when changing other parameters.

[sigvaldm]

It must probably be the Pdf's responsibility to have a debye function which, given density, returns the debye length?!

[diakodarian]

As the Debye length is dependent on the velocity distribution function it would be natural to add this functionality to the Pdf class.