beam parameter calculation based on fractions of particles

[skuschel]

add calculation of beam parameters for a particle analyzer, that represents particles of a bunch. Since the particle analyzer returns per particle properties this should probably be placed within a new class. Properties may be (to be completed) Charge, Emittance, normalized emittance, average P, Px, Py, Pz, Energy, Gamma, divergence,... spread of P, Px, Py, Pz, Energzy Gamma, divergence,...

Having a good and robust measure for the spread is essential. Therefore multiple methods should be implemented in the long go. There are two easy ways to go:

• calculate the smallest area or volume a certain fraction of particles is covering
• calculate the area of volume with more than half of the maximal particle density. Similar to the FWHM area of a laser focus size measurement.

This issue focusses on the first. The algorithm to do this probably requires some discussion.