run_simple: Simplest code to run a simulation loop

In IBAHCM/RPiR: Reproducible Programming in R

Simplest code to run a simulation loop

Description

A generic function to run a simulation loop for a fixed period of time. run_simple() will call step_function(initial.pop, ...) over and over until the time ends or step_function() reports that the experiment has ended.

Usage

run_simple(step_function, initial.pop, end.time, ...)

Arguments

step_function	Function to run a timestep (step_function()) which returns a list containing elements updated.pop with the updated population and end.experiment which is TRUE if the experiment has ended (FALSE if not)
initial.pop	Initial population data frame with columns corresponding to function requirements. This *must* include a time column so that run_simple() can check whether the end.time has been reached.
end.time	End time of simulation
...	(optionally) any other arguments for step_function(), e.g. parameters or timestep

Value

Data frame containing population history of simulation over time

See Also

run_simulation if you want a more flexible version of this function that will allow your step_function() to return just a data frame and will print some debugging information on request.

Examples

growth <- function(latest.df, growth.rate) {
current.count <- latest.df$count
growth.num <- current.count * growth.rate
next.count <- current.count + growth.num
next.time <- latest.df$time + 1
new.df <- data.frame(time=next.time, count=next.count)
finished <- next.count == 0
list(updated.pop=new.df, end.experiment=finished)
}
df <- data.frame(time=0, count=1)
results <- run_simple(growth, df, 100, growth.rate = 0.1)
plot_populations(results)

IBAHCM/RPiR documentation built on Jan. 12, 2023, 7:41 p.m.