Skip to main content

Coalescent simulations in continuous space

Project description

Simulates the coalescent for populations evolving in a spatial continuum under the extinction/recolonisation model. The simulations support:

  • A sample of n individuals with m loci at arbitrary locations on a torus of diameter L.
  • Arbitrary recombination rates between adjacent loci.
  • An arbitrary number of classes of event occuring at fixed rates.

Ercs supports both Python 2 and 3.


Here’s a quick example for the impatient:

import ercs
sim = ercs.Simulator(10)
sim.sample = [None, (3, 2), (6, 4), (7, 0)]
sim.event_classes = [ercs.DiscEventClass(u=0.5, r=1)]
pi, tau =

Full documentation for ercs is available at


Ercs depends on the GNU Scientific Library, which must be installed before the ercs module can be built. Fortunately, this is straightforward on most platforms. For example, on Debian or Ubuntu use:

$ sudo apt-get install libgsl0-dev

or on Fedora:

$ sudo yum install gsl-devel

GSL is available on most packaging systems; if it is not available on your platform, it can be installed from source.

Once GSL has been installed we can build the ercs module using the standard Python methods. For example, using pip we have

$ sudo pip install ercs

Or, we can manually download the package, unpack it and then run:

$ python build
$ sudo python install

Most of the time this will compile and install the module without difficulty.

It is also possible to download the latest development version of ercs from github.

Potential problems

On platforms that GSL is not available as part of the native packaging system (or GSL was installed locally because of non-root access) there can be issues with finding the correct headers and libraries when compiling ercs. For example, on FreeBSD we get something like this:

$ python build
... [Messages cut for brevity] ...
In file included from _ercsmodule.c:27:
lib/ercs.h:26:25: error: gsl/gsl_rng.h: No such file or directory
In file included from _ercsmodule.c:27:
lib/ercs.h:73: error: expected declaration specifiers or '...' before 'gsl_rng'
lib/ercs.h:94: error: expected specifier-qualifier-list before 'gsl_rng'
_ercsmodule.c: In function 'pyercs_simulate':
_ercsmodule.c:351: error: 'ercs_t' has no member named 'pi'
_ercsmodule.c:356: error: 'ercs_t' has no member named 'tau'
error: command 'cc' failed with exit status 1

This can be remedied by using the gsl-config program to set the the LDFLAGS and CFLAGS environment variables to their correct values:

$ CFLAGS=`gsl-config --cflags` LDFLAGS=`gsl-config --libs` python build


Ercs provides some test cases to ensure that the installation has gone smoothly. It is a good idea to run these immediately after installation:

$ python

It is also possible to run some tests on the low-level C library. To do this, cd to the lib directory and run:

$ make check

This will build the C library test cases and run them. If compilation fails, it may be necessary set LDFLAGS and CFLAGS as before:

$ make CFLAGS="`gsl-config --cflags`" LDFLAGS="`gsl-config --libs`" check

Tested platforms

Ercs has been successfully built and tested on the following platforms:

Operating system Platform Python Compiler
Ubuntu 8.04 i386 2.5.2 gcc 4.2.3
NetBSD 5.0 i386 2.7.3 gcc 4.1.3
Fedora 17 i386 2.7.3 gcc 4.7.2
Fedora 17 i386 3.2.3 gcc 4.7.2
Cygwin i386 2.6.8 gcc 4.5.3
Ubuntu 12.04 x86-64 2.7.3 gcc 4.6.3
Ubuntu 12.04 x86-64 3.2.3 gcc 4.6.3
FreeBSD 9.0 i386 3.2.2 gcc 4.2.2
FreeBSD 9.0 i386 2.7.2 gcc 4.2.2
FreeBSD 9.0 i386 3.1.4 clang 3.0
Solaris 11 x86-64 2.6.4 Sun C 5.12
Mac OSX 10.6.8 x86-64 2.6.1 gcc 4.2.1
Mac OSX 10.6.8 x86-64 3.2.3 gcc 4.2.1
Mac OS X 10.4.11 ppc 3.2.3 gcc 4.0.1
Mac OS X 10.4.11 ppc 2.7.3 gcc 4.0.1
Debian wheezy armv6l 2.7.3 gcc 4.6.3
Debian squeeze ppc64 2.6.6 gcc 4.4.5
Debian squeeze ppc64 3.1.3 gcc 4.4.5

The C library has additionally been compiled and tested with the following processors and compilers:

Platform Compiler
Linux 2.6.18-164.15.1.el5 x86_64 GNU/Linux Intel(R) C 11.0
Linux 2.6.32-5-amd64 x86_64 GNU/Linux gcc 4.4.5
Linux 2.6.32-5-amd64 x86_64 GNU/Linux clang 1.1
Linux 3.2.0-32-generic x86_64 GNU/Linux gcc 4.6.3
Linux 3.2.0-32-generic x86_64 GNU/Linux clang 3.0
Linux 3.2.27+ armv6l GNU/Linux gcc 4.6.3
Linux 2.6.32-5-powerpc64 ppc64 GNU/Linux gcc 4.4.5
Linux 2.6.32-5-powerpc64 ppc64 GNU/Linux clang 1.1
SunOS 5.11 11.0 i86pc i386 i86pc Sun C 5.12
SunOS 5.10 sun4u sparc SUNW,Ultra-4 Sun C 5.8

Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

ercs-1.0.1.tar.gz (127.1 kB view hashes)

Uploaded source

Supported by

AWS AWS Cloud computing Datadog Datadog Monitoring Facebook / Instagram Facebook / Instagram PSF Sponsor Fastly Fastly CDN Google Google Object Storage and Download Analytics Huawei Huawei PSF Sponsor Microsoft Microsoft PSF Sponsor NVIDIA NVIDIA PSF Sponsor Pingdom Pingdom Monitoring Salesforce Salesforce PSF Sponsor Sentry Sentry Error logging StatusPage StatusPage Status page