Particles / walkers [particles]

Specify the number of particles and their initial distribution

number: int

total number of particles

initial-distribution: string

method to set initial positions of particles. Currently available values:

  • random-global: initialize each particle randomly in the potential area

  • random-pos: initialize each particle randomly in one of the given positions

  • fractions-pos: initialize particles with fixed fractions at given positions

For -pos options you need to specify the wanted positions with pos1 to posN:

pos1: float or list of floats

Position in potential (list for more than one dimension)

For fractions-pos also the fractions have to be given.

fractions: list of float

Fractions of walkers that should be initalized at the specified positions. Needs to have one value for each position. The sum is normalized to one, so also absolute values can be specified. If the particles are not exactly distributable according to the fractions, the first position will get the remainder.

mass: float, optional

Mass of the particles, defaults to 1.0

seed: int, optional

Starting seed for the random number generator that is used if particles are distributed randomly

Example

This is an example where 100 particles are distributed on 3 positions of a 2D potential

[particles]
number: 100
initial-distribution: fractions-pos
pos1: 0.5, 0.5
pos2: 1.0, -0.1
pos3: -0.5, 1.1
fractions: 0.3, 0.4, 0.3