formula that defines the dependent variable as a linear model of independent variables; suppose the dependent variable has name z, for a idw detrended use z~1
data
SpatialPointsDataFrame: should contain the dependent variable, independent variables, and coordinates.
locations
object of class Spatial, or (deprecated) formula defines the spatial data locations (coordinates) such as ~x+y
nmax
number of nearest observations that should be used for a idw prediction, where nearest is defined in terms of the spatial locations. By default, all observations are used.
nmin
if the number of nearest observations within distance maxdist is less than nmin, a missing value will be generated; see maxdist.
p
value of smoothing parameter; we recommend using the parameter
found by minimizing the root-mean-square prediction errors using cross-validation. Default is 2.
progress
logical. Use TRUE to see the percentage of progress of the process and FALSE otherwise). Default progress=FALSE.