tRophicPosition is a colaborative project of Chris Harrod, Andrew L. Jackson, Claudio Quezada-Romegialli and others. It consists of an R package incorporating a Bayesian model for the calculation of consumer trophic position using stable isotopes with one or two baselines. It uses the powerful approach of Markov Chain Monte Carlo simulations provided by JAGS and the statistical language R.

As of 12th of October 2017, we are releasing the version 0.7.3 of the package, the third release version. If you find any error, please send it to and/or raise an issue in the GitHub page. Also you can also send a direct email to clquezada at

If you are interested in joining the tRophicPosition support group, do it at

NEWS (12 October 2017)


The stable version of tRophicPosition is hosted on CRAN, and is installed like any other package:


Remember to install JAGS for your platform as well.

The development version of tRophicPosition must be installed from GitHub. For this, install the package devtools, and then use the function install_github():

devtools::install_github("clquezada/tRophicPosition", build_vignettes = TRUE)

And then see the vignettes we have prepared to describe how to use the package:



tRophicPosition relies on some code from coda and dispRity. As dispRity is only available through GitHub, please install it from there. In any case, if not installed, tRophicPosition included the Bhattacharrya Coefficient (bhatt.coeff function) for convenience.

Future releases and how to get support

You are encouraged to use tRophicPosition with your own data, test the package and see if there are any issues or problems. You can send your questions or commentaries to the google group tRophicPosition-support or directly to the email trophicposition-support at You can send your questions to or even Facebook (stable isotope ecology group).

We are constantly working on future releases of tRophicPosition, so feedback is very much appreciated.


Things to do in tRophicPosition