RTRIM-shell scripts

Tool for PECBMS national species indices calculation

RTRIM-shell is a set of three R scripts developed by Statistics Netherlands, using RTRIM package for calculation of national species indices. Using this shell makes it easier to process large batches of species with specific model parameters at once. User guide is written right in the scripts (see especially first script). Note that the use of covariates is not included in the models. Because of the standardisation, it is not planned to include covariates in the future. RTRIM-shell is determined for calculation of national species indices sent to PECBMS coordination unit and therefore its models are locked for any changes.
RTRIM-shell can be downloaded here.


RTRIM-shell tutorial

We created a commented RTRIM-shell tutorial to speed up understanding how does RTRIM-shell work. Because of development of RTRIM-shell and other programs, this tutorial is planned to be regularly updated. Therefore, before you start RTRIM-shell analyses, it is worth to check the Tutorial and to download updated RTRIM-shell scripts.

Updated RTRIM-shell tutorial can be downloaded here.

Last update: 10th June, 2019
Update description: Data submission process changed – a zipped file will be sent by e-mail to the PECBMS coordinator

RTRIM package – TRIM in R – tool for own analyses

NOT for PECBMS national species indices

Examples in RTRIM package may be very useful for your own analyses. RTRIM package is a new version of the program TRIM which was rebuilt as an R package for the freely available and widely used open source statistical program R. Manual, documentation and help files in the R environment with several programming examples can be found on the CRAN website (Comprehensive R Archive Network). For any questions about the use of RTRIM, please contact

RTRIM contains the same methods and models for nature monitoring data as the original versions of TRIM. It can still work with the same input data and produces exactly the same output data, but as a package in R it can easily be integrated in other R programming processes. As a result of this there is a wider choice of options and settings for data analyses. New in this version is also the in-built possibility to combine results from other TRIM runs, e.g. to combine results obtained from the analysis of regions of a country into a single new output with a combined trend, indices and standard errors.

Being developed as R-package TRIM is made available for further developments by the large R-society. If you are interested in how TRIM was translated to the RTRIM-shell, see more info about TRIM also on the website of the Statistics Netherlands.


Old TRIM – TRIM in Delphi

Old version of the programme TRIM was originally developed some 25 years ago by Statistics Netherlands (Pannekoek and Van Strien, 1991) and was made available as a freeware stand-alone program. The program has had several updates since then, however, the original programming language (Delphi) has become outdated and rendered further developments.

The latest version is TRIM 3.54 (released in 2006) which is designed to run under 32-bits versions of Windows, as Windows98, Windows2000 and WindowsXP.

Warranty Disclaimer. This software and the accompanying documentation is provided „as is“. Statistics Netherlands disclaims all warranties, either expressed or implied.

TRIM can be downloaded together with a manual, a powerpoint presentation explaining TRIM for first users, and papers using the TRIM method. Alternatively, you can download TRIM as a part of the program BirdSTATs which enables to calculate indices and trends in batch mode to perform the statistical analysis for series of bird counts in the dataset.