Distance is a simple way of fitting detection functions to distance sampling data for both line and point transects. Adjustment term selection, left and right truncation as well as monotonicity constraints and binning are supported. Abundance and density estimates can also be calculated (via a Horvitz-Thompson-like estimator) if survey area information is provided.
For more information and examples of use take a look at this paper published in Journal of Statistical Software in May 2019.
We also maintain a set of example analyses at examples.distancesampling.org.
The easiest way to ensure you have the latest version of Distance, is to install Hadley Wickham's devtools package:
install.packages("devtools")
then install Distance from github:
library(devtools)
install_github("DistanceDevelopment/Distance")