SDraw draws five types of equal-probability samples from spatial objects, focusing on spatially balanced algorithms that are especially suited for environmental monitoring. SDraw implements the following:
- Halton Iterative Partitions (HIP)
- Balanced Acceptance Samples (BAS)
- Generalized Random Tesselation Stratified (GRTS)
- Simple Systematic Samples (SSS)
- Simple Random Samples (SRS)
The first four sample types (HIP, BAS, GRTS, and SSS) provide spatially balanced samples. SRS does not. Frame types can be points, lines, or polygons implemented as SpatialPoints*, SpatialLines*, or SpatialPolygons* objects.
See package help (help("SDraw")) and help for function sdraw (help("sdraw")) to get started. A list of available functions can be obtained with help(package="SDraw"). [For the newby: all of R is case sensitive. SDraw is different than sdraw.]
License: GNU General Public License
The author has found it best to install dependencies before attempting to install SDraw. To install dependencies, execute the following:
install.packages( c("spsurvey", "rgeos", "sp", "deldir"), repos="http://cran.r-project.org")
rgeos requires java. Java should be installed a priori. On Unix systems, the libraries needed for rgeos are cryptically named. Google 'install rgeos unix'.
The current stable release of SDraw can be installed like any other package:
install.packages( c("SDraw"), repos="http://cran.r-project.org")
The current development version of SDraw can be installed from GitHub. Assuming devtools is installed and loaded, the following should work:
install_github("tmcd82070/SDraw")
- Download the source tarball (the
tar.gz) from the current release - In R, execute the following:
install.packages( pkgs=file.choose(), type="source"" ) - A choose-file dialog will appear. Navigate to the
tar.gzfile and click "Open"
Issue library(SDraw) at the command prompt.