fit.tracevariog: Variogram Estimation
In geofd: Spatial Prediction for Function Value Data

Description Usage Arguments Details Value Author(s) References

View source: R/fit.tracevariog.R

Fits a parametric model to a empirical variogram and estimates covariance parameters. Aditionally all fitted variogram models are plotted for verification purpose.

fit.tracevariog(emp.trace.vari, models, sigma2.0, phi.0,
                fix.nugget=FALSE, nugget=0,
                fix.kappa=TRUE, kappa=0.5,
                max.dist.variogram=NULL)

`emp.trace.vari`	empirical trace-variogram. An object returned from the `trace.variog` function.
`models`	a character vector of correlation function names used in geoR against which empirical trace variogram will be fitted.
`sigma2.0`	initial value for the covariance parameter sigma^2 (partial sill).
`phi.0`	initial value for the covariance parameter phi (range).
`fix.nugget`	logical, indicating whether the `nugget` parameter should be estimated or not.
`nugget`	value for the nugget parameter.
`fix.kappa`	logical, indicating whether the `kappa` parameter should be estimated or not.
`kappa`	value of the smoothness parameter.
`max.dist.variogram`	a numerical value defining the maximum distance considered when fitting the variogram.

Variogram models and parameters

When the cov.model parameter is NULL a function determines the optimal model between spherical, exponential gaussian and matern using the received parameters. The arguments sigma2.0 and phi.0 are used as initial values for fitting each variogram model.

The parameters fix.nugget, nugget, fix.kappa, kappa and max.dist.variogram are the same for each variogram model specified in models.

A list with the following components:

`trace.vari`	choosed theoretical variogram model
`trace.vari.array`	vector of all fitted theoretical variogram models

Ramon Giraldo rgiraldoh@unal.edu.co,
Pedro Delicado pedro.delicado@upc.edu,
Jorge Mateu mateu@mat.uji.es.

Giraldo, R. (2009) Geostatistical Analysis of Functional Data. Ph.D. thesis. Universitat Politecnica de Catalunya.

Giraldo, R., Delicado, P. and Mateu, J. (2012) geofd: An R package for function-valued geostatistical prediction. Revista Colombiana de Estadistica. 35, 385-407.

geofd documentation built on Jan. 29, 2020, 5:08 p.m.