variogramModel: create or update variogram model

Description

This gives an easier interface to the parameters of the variogram model

Usage

rtopVariogramModel(model = "Ex1", sill = NULL, range = NULL, 
    exp = NULL, nugget = NULL, exp0 = NULL,
    observations = NULL, formulaString = obs~1) 
# S3 method for rtop
updateRtopVariogram(object, ...)
# S3 method for rtopVariogramModel
updateRtopVariogram(object, action = "mult", ..., 
              checkVario = FALSE, 
sampleVariogram = NULL, observations = NULL)

Value

The function helps creating and updating the parameters of the variogram, by using common names and simple update methods. This is mainly for manual fitting of the variogram. The automatic call to checkVario makes it easier to visualize the effect of the changes to the variogram

Arguments

model: variogram model, currently "Ex1" is the only implemented, see Skoien et al (2006)
sill: sill of variogram
range: range of variogram
exp: the exponent of the fractal part of the variogram, see Skoien et al (2006)
exp0: gives the angle of the first part of the variogram in a log-log plot (weibull type), should be between 0 and 2. See Skoien et al (2006)
nugget: nugget of point variogram
formulaString: formula that defines the dependent variable as a linear model of independent variables, see e.g. createRtopObject for more details.
object: either: object of class rtop (see rtop-package), or an rtopVariogramModel.
action: character variable defining whether the new parameters should be add(-ed), mult(-iplied) or replace the former parameters. Leaving the parameters equal to NULL will cause no change.
checkVario: logical, will issue a call tocheckVario if TRUE
sampleVariogram: a sample variogram of the data
observations: a set of observations
...: parameters to lower level functions

Author

Jon Olav Skoien

Examples

Run this code

if (FALSE) {
library(sf)
rpath = system.file("extdata",package="rtop")
observations = st_read(rpath,"observations")
# Create a column with the specific runoff:
observations$obs = observations$QSUMMER_OB/observations$AREASQKM
predictionLocations = st_read(rpath,"predictionLocations")
rtopObj = createRtopObject(observations,predictionLocations)
 # Fit a variogram (function also creates it)
rtopObj = rtopFitVariogram(rtopObj)
rtopObj = updateRtopVariogram(rtopObj, exp = 1.5, action = "mult", 
              checkVario = TRUE)
}