potential.kriging {RGeostats}R Documentation

Estimation using the Potential Method

Description

Estimation using the Potential Method

Usage

potential.kriging(db, dbgrd, dbout, dbtgt = NA, 
          model = model.input(), neigh = neigh.input(), degree = 0,
          nugget.grd = 0, nugget.tgt = 0, zmin=0, zmax=100, znumber=10,
          flag.up = TRUE, flag.grad = FALSE, flag.trans=TRUE,
          flag.part = 0, verbose = FALSE, radix = "Potential",
          modify.target = db.locmod())

Arguments

db

The db-class which contains the iso-potential information. This file must be defined in 1, 2 or 3-D. It must contain a 'layer' attribute.

dbgrd

The db-class which contains the gradient information. This file must contain as many 'gradient' variables as the space dimension. This file is compulsory.

dbout

The db-class which will contain the output estimation. This object must have the same space dimension as the other Db files: then the potential will be calculated for each cell. But the space dimension of this output file can be one degree less: in that case, the program will find the coordinate of the different iso-potential values per cell. This latter case will be refered to as Interpolation mode.

dbtgt

The db-class which contains the tangent information. This file must contain as many 'tangent' variables as the space dimension. This file is optional.

model

The model-class which contains the structure describing the spatial characteristics of the Potential variable. The model is composed of one or several basic structures, which belong to a limited set of authorized structures:

  • Gaussian

  • Cubic

  • Spline (2nd-order)

An additional nugget effect is also authorized.

neigh

The neigh-class which contains the neighborhood description. Currently only the Unique Neighborhood is coded.

degree

Degree of the Intrinsic Random Function used to describe the Potential Random Variable. Note that the degree must be 2 if the model contains the 2nd order Spline Generalized Covariance.

nugget.grd

The value of the nugget effect on the Gradient component

nugget.tgt

The value of the nugget effect on the Tangent component

zmin

In the Interpolation Mode (see comments on 'dbout'), this values gives the minimum for interpolating the elevation of the different isolines.

zmax

In the Interpolation Mode (see comments on 'dbout'), this values gives the maximum for interpolating the elevation of the different isolines.

znumber

In the Interpolation Mode (seed comments on 'dbout'), the search interval (between 'zmin' and 'zmax') is sampled at 'znumber' regularly spaced points to speed up the search.

flag.up

In the Interpolation Mode (seed comments on 'dbout'), the search is performed going from z_min up to z_max when 'flag.up' is TRUE; otherwise the search is performed downwards.

flag.grad

When TRUE, the estimation of the potential is calculated together with the gradient components. When FALSE, only the potential estimation is calculated.

flag.trans

When TRUE, the estimation is returned as the layer rank; otherwise the estimation is provided as the potential value.

flag.part

The user may decompose the contribution of the different elements in the potential estimation. This parameters must be specified as follows:

  • 0 the whole potential

  • 1 the gradient contribution

  • 2 the tangent contribution

  • 3 the isovalues contribution

  • 4 the (internal) drift contribution

  • 5 the external drift contribution

By linearity, the sum of all the components (flag.part>0) should be equal to the potential estimation (flag.part==0).

verbose

Verbose option

radix

Radix of the name given to the variables storing the results in the target Db.

modify.target

Decides whether or not the newly created variables will have their locator defined or not. For more information, see db.locmod.

Value

The target Db where the following variables have been added:


[Package RGeostats version 11.0.6 Index]