impose {particles}

Assign a force or constraint to a simulation

Description

This function adds a new force/constraint to the simulation and trains the it on the current particle graph. The parameters passed on to the training are using tidy evaluation from the rlang package. Depending on the force/constraint the data getting referenced is either the node or the edge data of the particle graph. Both forces and constraints manipulate position and velocity of the particles but they differ in when the are applied during a generation. First forces are applied sequentially and the resulting velocity is added to the resulting position after velocity_decay has been applied. After this operation any constraint is imposed on the results. In general, forces tends to calculate velocity adjustments, while constraints modify position and velocity directly, but this difference is not in any way enforced.

Usage

impose(simulation, constraint, ..., name, include = TRUE)

reimpose(simulation, name, ...)

unimpose(simulation, name)

wield(simulation, force, ..., name, include = TRUE)

rewield(simulation, name, ...)

unwield(simulation, name)

Arguments

simulation

A simulation object

constraint

A constraint object

...

Parameters passed on to the training of the force or constraint

name

The name of the force. For use when accessing the force at a later stage. If no name is given the force is accessible by its index in the stack.

include

The particles to be affected by this force. Defaults to every particle in the simulation (tidy eval)

force

A force object

Details

wield() and impose() adds forces and constraints to the simulation respectively. unwield() and unimpose() removes forces and constraints based on name or index. rewield() and reimpose() modifies existing forces and constraints based on name or index and retrains them.

Value

A simulation with the force or constraint added

Examples

graph <- tidygraph::create_notable('folkman')
graph |>
  simulate() |>
  wield(link_force)