intkrige-package {intkrige}

INTERVAL-VALUED KRIGING MODELS IN R

Description

An interval-valued extension of ordinary and simple kriging. Optimization of the function is based on a generalized interval distance. This creates a non-differentiable cost function that requires a differentiable approximation to the absolute value function. This differentiable approximation is optimized using a Newton-Raphson algorithm with a penalty function to impose the constraints. Analyses in the package are driven by the 'intsp' and 'intgrd' classes, which are interval-valued extensions of 'SpatialPointsDataFrame' and 'SpatialPixelsDataFrame' respectively. The package includes several wrappers to functions in the 'gstat' and 'sp' packages.

Functions

The package contains several generic functions such as plot, print, and summary to facilitate interval-valued analysis. In addition to these functions, the package also contains the following functions:

• intkrige Make predictions on interval-valued spatial data using interval-valued kriging.

• interval<- Create an interval-valued spatial object.

• intvariogram Simultaneously calculate the empirical variograms for an interval-valued spatial object.

• fit.intvariogram Automatically fit theoretical variograms to empirical variograms obtained from interval-valued spatial objects.

• intvCheck Visualize the variogram fits for interval-valued spatial objects.

• dist_cpp A c++ function to calculate great circle or Euclidean distances.

Data

• utsnow An interval-valued design ground snow load dataset for Utah.

• ohtemp An interval-valued 30 year mean temperature dataset for the Ohio River Basin.

• ohMap A SpatialPolygons shapefile for the Ohio River Basin.

Author(s)

Brennan Bean [e-mail]