First, compiles the vectorized population spatial maps into a series of binary raster PNG files, which is the format that SLiM understands and uses it to define population boundaries. Then extracts the demographic model defined by the user (i.e. population divergences and gene flow events) into a series of tables which are later used by the built-in SLiM script to program the timing of simulation events.

compile_model(
populations,
generation_time,
path = NULL,
resolution = NULL,
competition = NULL,
mating = NULL,
dispersal = NULL,
gene_flow = list(),
overwrite = FALSE,
force = FALSE,
sim_length = NULL,
direction = NULL,
slim_script = system.file("scripts", "script.slim", package = "slendr"),
description = ""
)

## Arguments

populations

Object(s) of the slendr_pop class (multiple objects need to be specified in a list)

generation_time

Generation time (in model time units)

path

Output directory for the model configuration files which will be loaded by the backend SLiM script. If NULL, model configuration files will be saved to a temporary directory.

resolution

How many distance units per pixel?

competition, mating

Maximum spatial competition and mating choice distance

dispersal

Standard deviation of the normal distribution of the parent-offspring distance

gene_flow

Gene flow events generated by the gene_flow function (either a list of data.frame objects in the format defined by the gene_flow function, or a single data.frame)

overwrite

Completely delete the specified directory, in case it already exists, and create a new one?

force

Force a deletion of the model directory if it is already present? Useful for non-interactive uses. In an interactive mode, the user is asked to confirm the deletion manually.

sim_length

Total length of the simulation (required for forward time models, optional for models specified in backward time units which by default run to "the present time")

direction

Intended direction of time. Under normal circumstances this parameter is inferred from the model and does not need to be set manually.

slim_script

Path to a SLiM script to be used for executing the model (by default, a bundled backend script will be used)

description

Optional short description of the model

## Value

Compiled slendr_model model object

## Examples

# spatial definitions -----------------------------------------------------

# create a blank abstract world 1000x1000 distance units in size
map <- world(xrange = c(0, 1000), yrange = c(0, 1000), landscape = "blank")

# all spatial slendr objects can be visualised with a function plot_map()
plot_map(map)

# create a circular population with the center of a population boundary at
# [200, 800] and a radius of 100 distance units, 1000 individuals at time 1
# occupying a map just specified
pop1 <- population("pop1", N = 1000, time = 1,
map = map, center = c(200, 800), radius = 100)

# printing a population object to a console shows a brief summary
pop1

# create another population occupying a polygon range, splitting from pop1
# at a given time point (note that specifying a map is not necessary because
# it is "inherited" from the parent)
pop2 <- population("pop2", N = 100, time = 50, parent = pop1,
polygon = list(c(100, 100), c(320, 30), c(500, 200),
c(500, 400), c(300, 450), c(100, 400)))

pop3 <- population("pop3", N = 200, time = 80, parent = pop2,
center = c(800, 800), radius = 200)

# move "pop1" to another location along a specified trajectory and saved the
# resulting object to the same variable (the number of intermediate spatial
# snapshots can be also determined automatically by leaving out the
# snapshots =  argument)
pop1_moved <- move(pop1, start = 100, end = 200, snapshots = 10,
trajectory = list(c(600, 820), c(800, 400), c(800, 150)))
pop1_moved

# many slendr functions are pipe-friendly, making it possible to construct
# pipelines which construct entire history of a population
pop1 <- population("pop1", N = 1000, time = 1,
map = map, center = c(200, 800), radius = 100) %>%
move(start = 100, end = 200, snapshots = 10,
trajectory = list(c(400, 800), c(600, 700), c(800, 400), c(800, 150)))

# a population boundary at a given time can be "manually" created by calling
# the function set_range() -- here we extend the pipeline from the previous
# command to set the final spatial map of pop1 to another polygon
pop1 <-
population(
"pop1", N = 1000, time = 1,
map = map, center = c(200, 800), radius = 100
) %>%
move(
start = 100, end = 200, snapshots = 10,
trajectory = list(c(400, 800), c(600, 700), c(800, 400), c(800, 150))
) %>%
set_range(time = 300, polygon = list(
c(400, 0), c(1000, 0), c(1000, 600), c(900, 400), c(800, 250),
c(600, 100), c(500, 50))
)

# spatial boundaries can be plotted with a function plot_map()
plot_map(pop1)

# population ranges can expand by a given distance in all directions
pop2 <- expand_range(pop2, by = 200, start = 50, end = 150, snapshots = 10)

# we can check the positions of all populations interactively by plotting their
# ranges together on a single map
plot_map(pop1, pop2, pop3)

# gene flow events --------------------------------------------------------

# individual gene flow events can be saved to a list
gf <- list(
gene_flow(from = pop1, to = pop3, start = 150, end = 200, rate = 0.15),
gene_flow(from = pop1, to = pop2, start = 300, end = 330, rate = 0.25)
)

# compilation -------------------------------------------------------------

# location where to save slendr model configuration files
model_dir <- paste0(tempdir(), "_slendr_model")

# compile model components in a serialized form to dist, returning a single
# slendr model object (in practice, the resolution should be smaller)
model <- compile_model(
populations = list(pop1, pop2, pop3), generation_time = 1,
path = model_dir, overwrite = TRUE,
resolution = 10, sim_length = 500,
competition = 5, mating = 5, dispersal = 1
)

# serialized models can be read from disk to their R representation again