Dear distance-sampling list,
We are pleased to announce the release of new versions of our R packages
mrds, which are available in the usual way you obtain package updates in R. The new release adds the ability to fit detection functions (CDS and MCDS) using the same optimizer used by
Distance for Windows.
This requires downloading a compiled file MCDS.exe into an R library directory, and is currently only supported under Windows operating systems. This new feature may be of use for those encountering difficulties fitting detection functions (e.g., convergence problems) and also those with inherently “difficult” distance sampling data - e.g., data with a spike in the detection function close to zero or overdispersion (many non-independent detections, such as is common in camera trap distance sampling). There are also circumstances with the MCDS.exe optimizer is faster than the R-based one, which may be of particular help when using a nonparametric bootstrap for variance estimation. A vignette giving examples and more information is available on our DistanceExamples web page (the vignette is entitled “Alternative optimization engine for fitting detection functions” and a direct link to the html file is here ). If you encounter any difficulties in using this new enhancement, please let us know.
Please note that this new feature is not currently available under non-Windows operating systems (e.g., Mac or Linux) and we also do not recommend using it if you analyze double-platform data using the
A full list of changes and updates is given below.
Thanks to those who have made feature requests or reported issues. If you do find any problems, or want to suggest a new feature, please feel free to raise an issue at https://github.com/DistanceDevelopment/distance-bugs/issues or in the github page for each package
Changes in version 1.0.8
Changes in version 2.2.9
Distance Development Team
Centre for Research into Ecological & Environmental Modelling
University of St. Andrews