OrdKrig: Ordinary local kriging and inverse distance weighting

In JBrenn/SpatialInterpol: Spatial Interpolation of Soil Variables | Province of Bolzano

Description

Ordinary local kriging and inverse distance weighting. Using global variogram estimation (see variogram) and krige::krige.locations, krige::idw.locations (see krige), providing GEOtif raster output according to a given raster mask.

Usage

OrdKrig(wpath = "/home/jbre/R/OrdKrig", 
        datafolder = "raw", rastermask = "mask/Mask_master.tif",
        inverseDistWeigths = FALSE, local = TRUE,
        variable = "Humus____",  npix = 100,
        cutoff = c("AdigeVenosta"=400, "Adige"=400, "Venosta"=450), 
        anis_deg = c("AdigeVenosta"=0, "Adige"=0, "Venosta"=90), 
        anis_ax = c("AdigeVenosta"=.5, "Adige"=.5, "Venosta"=.5),
        psill = c("AdigeVenosta"=1, "Adige"=1, "Venosta"=1), 
        nugget = c("AdigeVenosta"=1, "Adige"=1, "Venosta"=1),
        nmax = c("AdigeVenosta"=12, "Adige"=12, "Venosta"=12), 
        nmin = c("AdigeVenosta"=1, "Adige"=1, "Venosta"=1),
        omax = c("AdigeVenosta"=3, "Adige"=3, "Venosta"=3),
        idp = c("AdigeVenosta"=2.0, "Adige"=2.0, "Venosta"=2.0),
        var_model="Sph",
        validation = FALSE, kfold=5,
        coordsys = "+proj=utm +zone=32 ellps=WGS84")

Arguments

wpath	working path containing data files in datafolder, as well as a raster mask in rastermask.
datafolder	folder within wpath containing raw data files
rastermask	folder within wpath containing raster mask
inverseDistWeigths	boolean, if TRUE method is invers distance weighting (IDW), else method is local kriging
local	boolean, if TRUE local kriging, else global kriging, see krige
variable	character, variable name to interpolate, choose according to the column name of the input data files
npix	grid resolution of the input map. If the resolution of the raster mask coarser then npix the raster mask is resampled to npix in order to define estimation locations
cutoff	see variogram, also used for the range argument in vgm
anis_deg	see anis argument in vgm, main axis direction
psill	see vgm
nugget	see vgm
nmax	see krige
nmin	see krige
omax	see krige
idp	see idw
model	see fit.variogram
validation	boolean, if TRUE fold validation is run, no map output
kfold	see createFolds
coordsys	characeter, definition of coordinate system, see crs

Details

Each input file in datafolder has to contain geographic coordinates with the column names x_Coord and y_Coord and variable values to interpolate. Parameters for the functions vgm, fit.variagram, variogam, krige and idw are gven by named vectors. Names refer to the zone names (namezone) interpolationis done for, data input files have to named accordingly: Masterfile_namezone.txt. An example data folder can be found here here.

Author(s)

Johannes Brenner, [e-mail]

JBrenn/SpatialInterpol documentation built on May 7, 2019, 7:39 a.m.