Command Line Arguments

scrm is uses a syntax compatible with the popular program ms. There are, however, a few differences to ms:

For all other options, you can also refer to ms' manual to get a detailed description of what the commands are doing. scrm should happily execute any ms command that does not contain -c and -s. Also scrm has somewhat stricter requirements regarding the order of arguments if population admixture (-es) is involved.

General Syntax

The command line options for scrm look like

scrm <nsamp> <rep> [...]

where nsamp is the total number of samples taken (in all populations and at all times), rep is the number of independent loci/chromosomes to generate and the [...] is an optional placeholder for an arbitrary number of command flags described below.

Basic Parameters

Recombination

Population structure & migration

In all commands, migrations rates M = 4*N0*m, where m is the fraction of a population that is replaced with migrants from other populations each generation (looking forwards in time).

Population size changes

Summary Statistics

Reproducibility

Time specific parameters

The command this section all have a time t as first parameter. Changes made by the commands affect the time from t further back into the past. All times in units of 4*N0 generations.

Population structure & migration

Population size changes

Population Splits & Merges

Sequence specific parameters

The following commands change the model parameters from at a sequence position s.