Home

Distance - an R package for distance sampling analysis

Rationale

The most feature-complete distance sampling analysis package (mrds) is not very user friendly. Distance provides a simple interface to the functionality of mrds. Distance is a wrapper around mrds, so eventually it is hoped that all of the features of mrds will be incorporated.

Problems?

For advice about distance sampling analyses and survey methodology in general, try the distance sampling e-mail list. If you think you've found a bug in Distance, you can report it on github.

Other pages in this wiki

• Feature comparison between Distance and other packages.
• Distance sampling resources - where else to find information.
• Optimisation Issues - tips on how to deal with optimisation issues in Distance.
• Using dht for abundance estimation inside and outside the ds function.
• COMING SOON: One-sided transects - how to deal with them in Distance.

Example analysis

From the examples in Distance

  library(Distance)
  # Golf tee data
  data(book.tee.data)
  # just take the data from observer 1
  tee.data<-book.tee.data$book.tee.dataframe[book.tee.data$book.tee.dataframe$observer==1,]
  # run the analysis, selecting number of adjustments by AIC
  # but constraining for monotonicity
  ds.model<-ds(tee.data,4,monotonicity="strict")
  # usual R functions
  summary(ds.model)
  plot(ds.model)

Coming soon

The aim is for Distance to include most of the functionality of mrds. If there is a particular feature that you would like to see please log it as an Issue.

References

Buckland, S.T., Anderson, D.R., Burnham, K.P., Laake, J.L., Borchers, D.L., and Thomas, L. (2001). Distance Sampling. Oxford University Press. Oxford, UK.

Buckland, S.T., Anderson, D.R., Burnham, K.P., Laake, J.L., Borchers, D.L., and Thomas, L. (2004). Advanced Distance Sampling. Oxford University Press. Oxford, UK.

Royle, J.A., Dawson, D.K, and Bates, S. Modeling Abundance Effects in Distance Sampling (2004). Ecology 85(6) pp. 1591-1597