Lib.rs

SLiM simulation wrapper

This is a small program to wrap SLiM grid runs. It targets cases in which per-cycle, tabular output is the primary output of the simulation. Any .csv-like output is automatically consumed by this wrapper, annotated with parameter values, and batched into larger files. With shorter simulations, this saves a lot of time spent on disk writes and compression. The program also is able to run many instances of SLiM in parallel, speeding up simulations over large parameter grids.

Output is written as a sequence of parquet files output_{i}.parquet. Many parquet readers know how to treat a directory as a single big parquet file.

Installing and using the program

If you are using Nix, you can try slim-runner by running

nix shell github:EgorLappo/slim-runner

You can also use cargo to install slim-runner. First, install Rust with rustup. Then, run

cargo install --git https://github.com/EgorLappo/slim-runner.git   

The executable is called slim-runner. The usage instructions are

$ slim-runner --help
Launch SLiM grid runs

Usage: slim-runner [CONFIG]

Arguments:
  [CONFIG]  [default: slim_config.toml]

Options:
  -h, --help     Print help
  -V, --version  Print version

Config format

Configuration is done through a .toml file that contains several top-level tables.

The table settings contains global parameters such as SLiM script location, number of available cores, etc.

[settings]
# global random seed (optional, defaults to 0)
seed = 231
# number of replicates per parameter set (optional, defaults to 1)
replicates = 10
# slim script to run
script = "example_script.slim"
# output directory
output_dir = "output"
# number of parallel instances of SLiM to use (optional, defaults to 1)
cores = 6
# interval to write output to disk in parameter sets (optional, defaults to 100)
write_every = 1000
# annotate the output log files with grid parameter values (optional, defaults to `true`)
annotate = true
# only run first `limit' simulations (optional, for debugging purposes)
limit = 100
# custom slim executable path (optional, defaults to `slim`) 
slim_exe = "/path/to/slim"

The parameters are set in the grid table. Valid parameter values are a string, a number, a list of number, and a range of values.

[grid]
N = [500, 1000, 2000, 5000]
s = { from = 0, to = 0.1, num = 11 }
h = { from = 0, to = 1, step = 0.25 }
mu = 10e-7
rbp = 10e-8
tag = "example"

The ranges are always inclusive of the to value: for example, the range for h above would be expanded to h=[0,0.25,0.5,0.75,1.0].

The string parameters are only used as tags in case you want to somehow tag the whole run of slim-runner.

Writing SLiM scripts

slim-runner works well with simulations that make use of logging or other standard output. This means that currently it does not deal with any output dumped at the end of the simulation explicitly, unless you manually make it into a csv file.

Types. All numerical parameters are passed as floats, so don't forget to cast required parameters to integers. For example, write

sim.addSubpop("p1", asInteger(N));

Required argument. The SLiM script is always passed an argument titled outfile, and this file handle should be used for the Logfile:

log = community.createLogFile(outfile, logInterval=10, flushInterval=1000);
log.addCycle();
log.addMeanSDColumns('k', 'sim.subpopulations.individuals.countOfMutationsOfType(m1);');

You can use this argument for debugging your output, and slim-runner will then pass /dev/stdout to SLiM to read this file from standard output. Many simulation runs will then be combined into bigger files and written to disk.

Annotation. If annotate = true in the config, the output for each will be annotated with the grid parameter values and the replicate number. If annotate = false, only the replicate number will be recorded. Use this if you want to annotate the table yourself from inside slim, e.g. if you want to record transformed parameters.

TODOs

• Parse environment variables in output/executable paths
• "Workers" that process other kinds of data (e.g. capture built-in SLiM outputs)