A proper introduction to the soilDB package is now available here. Installation and basic usage are covered. More detailed, task-specific documentation on aqp and soilDB will be available soon. read more
Blog Archives
Extracting an image chunk from a collection of Large MrSid Images
Recently needed to extract a small "chunk" from a collection of adjacent MrSid mosaics, each about 4Gb in size. Once again, GDAL came to the rescue, and saved much time and agony wile working with very large, compressed, and proprietary-format files. T...
soilDB Demo: Processing SSURGO Attribute Data with SDA_query()
Mapping near Paloma, CA This image has nothing to do with the following content. A quick example of how to use the USDA-NRCS soil data access query facility (SDA), via the soilDB package for R. The following code describes how to get component-level so...
R Quickie: Custom Panel Functions and Default Arguments
Sometimes the basic functionality in lattice graphics isn't enough. Custom "panel functions" are one approach to fully customizing the lattice graphics system. Two examples are given below illustrating how to define an (inline) custom panel function fo...
AQP Kick-Start
A fun kick-starter for anyone interested in working with soil profile data in R, via AQP. See in-line comments for details. Up next, profile slicing and aggregation. read more
Dissimilarity Between Soil Profiles: A Closer Look
Continuing the previous discussion of pair-wise dissimilarity between soil profiles, the following demonstration (code, comments, and figures) further elaborates on the method. A more in-depth discussion of this example will be included as a vignette w...
A Graphical Explanation of how to Interpret a Dendrogram
Dendrograms are a convenient way of depicting pair-wise dissimilarity between objects, commonly associated with the topic of cluster analysis. This is a complex subject that is best left to experts and textbooks, so I won't even attempt to cover it her...
AQP / soilDB Demo: Dueling Dendrograms
Previously, soil profile comparison methods from the aqp package only took into account horizon-level attributes. As of last week the profile_compare() function can now accommodate horizon and site-level attributes. In other words, it is now possible t...
AQP Demo: Interfacing with PedonPC Databases using the ‘soilDB’ Package
Here is a quick, draft demo on extracting soils data from a PedonPC database, and performing some common analysis with functions from AQP. The newly released soilDB package makes it possible to rapidly extract soils data from PedonPC, local NASIS, and ...
A Quick Demo of SoilProfileCollection Methods and Plotting Functions
Here is a quick demo of some of the new functionality in AQP as of version 0.99-9.2. The demos below are based on soil profiles from an archive described in (Carre and Girard, 2002) available on the OSACA page. A condensed version of the collection is ...
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
