The Dendrochronology Program Library in R (dplR)
dplR is a software package in the R statistical programming environment for tree-ring analyses. R is the world's preeminent open-source statistical computing environment where users can contribute packages, which are freely available on the internet. dplR can read standard format files and perform several standard analyses. These include interactive detrending, chronology building, and calculating standard descriptive statistics. The package can also produce a variety of publication quality plots. dplR is actively and lovingly developed by a half dozen people in several countries.
A continuous wavelet transform of a long tree-ring crhonology produced by the wavelet.plot() function
There are two papers that describe dplR:
Bunn, A.G. 2008. A dendrochronology program library in R (dplR). Dendrochronologia, 26: 115-124.
PDFs of these papers can be found here. Please cite dplR properly when using the package.
There was a workshop on dplR in May, 2013 at the AmeriDendro conference. Here is the script from that workshop. The script might contain typos and errors since a lot of it was constructed on the fly at the workshop. Use with caution. Much of that code uses the Mt. Angeles, wa084.rwl ring-width file which is available on the ITRDB. But any rwl file will suffice including the onboard datasets like ca533, co021, etc.
Here is the link to the published library on the Comprehensive R Archive Network where you can download the source code or precompiled binaries for the current release. Within R, dplR can be installed, loaded, and the help pages can be seen via:
> install.packages("dplR")
> library(dplR)
> ?dplR
dplR is updated regularly. Please update to the current version from time to time. It's good R practice:
> update.packages()
The current development version of dplR can be found on R-Forge. There are several developers actively working on dplR and contributing code. Please let us know what features you would like to see added and report any bugs. You can get a (potentially unstable) daily snapshot of the development version of dplR in R via:
> install.packages("dplR", repos="http://R-Forge.R-project.org")
