ipdw
The R
package
ipdw provides the
functionality to perform interpolation of georeferenced point data using
inverse path distance weighting. Interpolation is accomplished in two
steps. First, path distances are calculated from each georeferenced
(measurement) point to each prediction point. Path distances, which
honor barriers in the landscape, are calculated based on cell-to-cell
movement through an underlying Raster
object that represents movement
cost. These path distances are subsequently used as interpolation
weights. The two-step routine follows the order of operations described
in Suominen et al. (2010) substituting the ESRI path distance algorithm
with the gdistance
wrapped version of the igraph
adjacency
algorithm.
The ipdw package was developed with coastal marine applications in mind where path distances (as the fish swims) rather than Euclidean (as the crow flies) distances more accurately represent spatial connectivity. Interpolation of sparse grids in coastal areas otherwise end up bleeding through land areas.
Installation
Stable version from CRAN
install.packages("ipdw")
or development version from GitHub
install.packages('devtools') # package devtools needed
devtools::install_github("jsta/ipdw")
Examples
see vignette
References
Joseph Stachelek and Christopher J. Madden (2015). Application of Inverse Path Distance weighting for high density spatial mapping of coastal water quality patterns. International Journal of Geographical Information Science preprint | journal
Tapio Suominen, Harri Tolvanen, and Risto Kalliola (2010). Surface layer salinity gradients and flow patterns in the archipelago coast of SW Finland, northern Baltic Sea. Marine Environmental Research journal