Simulation-Based Maximum Likelihood Parameter Estimation

An estimation method that can use computer simulations to approximate maximum-likelihood estimates even when the likelihood function can not be evaluated directly. It can be applied whenever it is feasible to conduct many simulations, but works best when the data is approximately Poisson distributed. It was originally designed for demographic inference in evolutionary biology. It has optional support for conducting coalescent simulation using the 'coala' package.

Project Status: Active - The project has reached a stable, usable state and is being actively developed. Linux Build Status Windows Build status Coverage Status CRAN Status

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Jaatha is an estimation method that uses computer simulations to produce maximum-likelihood estimates even when the likelihood function can not be evaluated directly. It can be applied whenever it is feasible to conduct many simulations, but works best when the data is at least approximately Poisson distributed.

Jaatha was originally designed for demographic inference in evolutionary biology. It has optional support for conducting coalescent simulation using the coala R package, but can also be used for different applications.

Jaatha is implemented as an R package and available on CRAN.


Jaatha can be installed from CRAN using the install.packages command:



The R package includes an introduction vignette that explains how to conduct a jaatha analysis. A second vignette describes how jaatha can be used together with coala for demographic inference.

Further help is provided using R's help system, in particular via ?jaatha, ?create_jaatha_model and ?create_jaatha_data.

You can ask questions on jaatha's mailing list: jaatha (at) googlegroups (dot) com


If you encounter problems when using jaatha, please file a bug report or mail to jaatha (at) googlegroups (dot) com.


Jaatha's original algorithm is described in the publication:

Jaatha: a fast composite-likelihood approach to estimate demographic parameters. Molecular Ecology 20(13):2709-23 (2011).

The revised version of the algorithm that is implemented in this package is described in:

L.A. Mathew, P.R. Staab, L.E. Rose and D. Metzler: Why to account for finite sites in population genetic studies and how to do this with Jaatha 2.0. Ecology and Evolution (2013).


Jaatha is developed openly on GitHub. Feel free to open an issue there if you encounter problems using Jaatha or have suggestions for future versions.

The current development version can be installed using:



jaatha 3.2.0

  • Adds the cores_per_run to boot_jaatha which can be set to use more than one CPU core for each replica (#128).
  • Coala support: Adds JSFS summary options folded_sums, which calculates the standard JSFS coarsening from an unpolarized spectrum (#130).
  • Now tries to continue the estimation even when a few simulations return errors (#131).
  • Skips tests if testthat is not available (#132).
  • Adds new options final_sim and zoom_in_steps to the main jaatha method (#134).
  • Fixes a bug that lead to a broken assertion when jaatha was used on a model with one parameter and repetitions was greater than one (#135). Thanks to Amaya Romero for reporting and locating this bug!.

jaatha 3.1.1

  • Fixes broken suppression of messages with verbose argument of the jaatha function (#118).
  • Removes a buggy check for summary statistics that are insensitve about the parameters introduced in version 3.1.0. Together with the previous bug, this could lead to false results in some applications of jaatha. For any runs conducted with that version, check if the output contained an estimated likelihood of 1 and repreat the runs with the new version if so (#124).
  • Adds more assertions to the code (#120).

jaatha 3.1.0

  • Adds a limit to the number of cached simulations (#103).
  • Adds the random initialization method for using random starting positions (#104).
  • Also captures model and data in the pars argument of an jaatha analysis and removed the corresponding arguments from boot_jaatha (#105).
  • Adds a custom print methods for Jaatha's results (#106).
  • Optimizes scheduling of simulations based on their duration. If simulations take more than five seconds, the mc.preschedule argument of parallel::mclapply is now set to FALSE (#107).
  • Adds the block_width argument to jaatha (#108).
  • Also exports create_jaatha_model.function and
    create_jaatha_model.coalmodel as functions (#109).
  • Increases robustsness to not-converging GLMs. If a GLM fails to converge, now only the current repetition is aborded instead of the compelete analysis (#110, #111).
  • Dump frames to tempdir() on simulation errors (#113).

jaatha 3.0.0

  • This version is a complete rewrite of the package. The R interface completely redesigned, and should now be more similar to other R packages.
  • All functionality for coalescent simulation was removed from the package, and is now available via the separate package coala.
  • The use of jaatha as a general method is now more prominent.
  • The documentation was revised. The vignettes are now included in the package.
  • More methods for generating starting positions were added to the package.
  • Jaatha now uses the boot package for bootstrapping calculations.
  • Internally, all S4 classes where replaced with R6 classes to increase the performance.

jaatha 2.7.0

  • Implement a candidate loci approach for selection. So far only for internal testing.
  • Allow for gamma distributed recombination and mutation rates between loci for genomic parameters (mutation and recombination rates).
  • Bug fix: Fix two bugs with calculation of confidence intervals.
  • Fix a harmless memory leak in experimental code (#19)

jaatha 2.6.0

  • Switched unittests from RUnit to testthat
  • Added a Rcpp function to parse tree from ms(ms) output for seq-gen. This should make seq-gen less platform dependent (it still requires a Unix platform).
  • Add a subset parameter to Jaatha.confidenceIntervals that allows to distribute the calculation on multiple machines.
  • Bug fix: in 2.5.1, the ms output file was not delete when using seq-gen. This can cause Jaatha to fail if the disk runs out of space (#14).
  • Bug fix: Fixed a severe bug in the Jaatha.confidenceIntevals function. There often parameters different from the maximum likelihood estimates were used to calculate the confidence intervals (#15).

jaatha 2.5.1

  • Made it possible to use seq-gen together with msms (Linux only).
  • Bug fix: Fixed a bug that caused seq-gen to fail if the mutation parameter was not the last model parameter.

jaatha 2.5.0

  • Fixed wrong description of N0 as size of the ancestral population in the documentation (#4)
  • Fixed an bug with made jaatha abort when a point was slightly outside parameter range (#5)
  • Fixed bug in calculation of JSFS introduced in 2.4-1 (#7)
  • Now old simulations are actually reused (#8)
  • It is no longer necessary to have a simulation program that can simulate all groups (#6)
  • Different groups now really use different simulation programs
  • Simplified internal simulation program interface
  • Print dispatch for demographic model
  • Modularized parsing of simulation output
  • Models in different groups can now use different simulation software
  • Now Jaatha simulates more data if it fails to fit the GLM
  • Allow GLM more steps to converge
  • Different Groups can now have different summary statistics
  • Prioritizing system for simulations programs
  • Removed additional tmp-folders
  • Removed dependency on foreach
  • Changed dependency from dplyr to reshape2
  • Removed optional logging into a file

jaatha 2.4.0

  • Jaatha.initialSearch() now divides the parameter space by all axis in turn, which makes the number of block linear instead of exponential in the parameter number.
  • Add an optional border to smoothing type summary statistics with is fitted via traditional transformations.
  • Using dplyr instead of plyr for converting JSFS into data frames because it is significantly faster.
  • Striped unused components from the glm objects.

jaatha 2.3.0

  • Removed epsilon. We now stop the refined search after the likelihood did not improve for 10 consecutive steps.
  • Removed weight parameter to down-weight old simulations, because it had no measurable effect on the estimates.
  • Support for multiple groups of loci
  • Possibility to smooth arrays of arbitrary dimension

jaatha 2.2.0

  • Added function for calculating BCa confidence intervals
  • Added rerun option to initial & refined search
  • Switched form doMC to multicore for parallelization
  • Support for multiple independent summary statistics, even though this is not yet used in the default front end.
  • Differentiated between unit and integration tests and moved the unit tests back into the package.
  • Reworked the reusing of simulations from previous steps in the refined search. Now only simulations that actually are inside the current block are reused.
  • Removed the "score". We are always using the log-likelihood now.
  • Added support for a new "poisson.smoothing" type of summary statistics.
  • Fixed problem with naming of temporary directories if Jaatha was executed multiple times in different threads
  • Fixed problem with Rcpp in size_t on 64 bit windows
  • Fixed warning messages in cpp files
  • Updated Makevars

jaatha 2.1.0

  • Removed the "externalTheta" option to simplify further development
  • Rewrote and cleaned up many of the internal functions
  • Further separated Jaatha and Demographic Model to simplify use of Jaatha in other areas
  • Added caching for log factorials
  • Ported msFile2jsfs to Rcpp
  • Removed vignettes from the package due to their long build time; The pdfs will be provided on Jaatha's homepage instead
  • Added citation information to the package
  • Added link to github repo to package description
  • Removed unused optimization strategies
  • Bugfix: Changed the example fasta file for compatibility with next ape version
  • Bugfix: Fixed encoding issue with bibtex for the packages vignette
  • Bugfix: Removed debug functions in C++ files that prevented installation on R-2.14

jaatha 2.0.0

  • Updated Documentation and Vignette
  • New Feature: Added caching of ms and seqgen commands
  • Changed Feature: Made use of /dev/shm optional
  • Bugfix: Multiple tmp-dirs used during multicore refined search
  • Bugfix: Multiple searches for seqgen binary if running on multiple cores
  • Fixed a bug with one parameter models
  • Added support for seqgen
  • GLM fitting algorithm can now take more steps to converge
  • Updated the vignette
  • Ported to Rcpp
  • Added parallelization using doMC.
  • Some improvements to the UI.
  • Updated copyright information.
  • Added import from ape.
  • Updated the vignette.
  • Use /dev/shm for temp files if available
  • Added "folded" option to use a folded JSFS
  • Added documentation for fasta2jsfs()
  • Made fasta2jsfs calculate the folded JSFS if no outgroup is given.
  • Reworked the demographic model class to be more flexible and consistent.

Reference manual

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3.2.1 by Paul Staab, 2 years ago

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Browse source code at

Authors: Paul Staab [aut, cre] , Lisha Mathew [aut] , Dirk Metzler [aut, ths]

Documentation:   PDF Manual  

Task views:

GPL (>= 3) license

Imports assertthat, R6, parallel, stats, utils

Suggests boot, coala, knitr, rmarkdown, testthat

See at CRAN