CCG Programs

Description Usage Arguments Details Value

varmodelR auto fits variogram models. This version is less flexible the pure Fortran program. It is designed to support modelling of univariate variogram models. For multivariate models it is designed to model the direct variograms with the cross-variograms modeled in the vl_lmc function. A large number of structures can be modelled (in additiona to the nugget effect), but they all must have the same structure type, orientation, and range parameters. If these parametrs are 'wildcards' they may produce structures with different type and range.

varmodelR(expdata, sysout, ndir = 1, nst = 10, c0 = "0.05:0.25",
  it = 1, cc = "?", azm = 0, dip = 0, tilt = 0, ahmax = "?",
  ahmin = "?", avert = "?", fit = TRUE, maxiter = 1e+05,
  vargsill = 1, vario = c(1, 2), npairswt = TRUE, invdistwt = TRUE,
  minpairs = 10, fixhmaxvertanis = FALSE, hmaxvertanis = 10,
  fixhmaxhminanis = FALSE, hmaxhminanis = 1)

`expdata`	Character: name of input GSLIB-format experiemental variogram file without the extnsion part, and extension of ".out" is added for compatibility with `vl_lmc`.
`sysout`	Character: name of output GSLIB-format variogram model file without the extnsion part, and extension of ".var" is added for compatibility with `vl_lmc`.
`ndir`	Numeric integer: number of directions to model.
`nst`	Scalar integer: number of structures to model. Default 10.
`c0`	Scalar numeric: nugget effect or wildcard.
`it`	Scaler integer: structure type in range 1:5 or wildcard.
`cc`	Scalar numeric: variance contribution or wildcard.
`azm`	Numeric vector: azimuth in GSLIB convention or wildcard. Wildcard not recommended. Must be length `ndir` with first value being major axis azimuth.
`dip`	Numeric vector: dip in GSLIB convention or wildcard. Wildcard not recommended. Must be length `ndir` with first value being major axis dip.
`tilt`	Scalar numeric: tilt or major axis in GSLIB convention or wildcard. Wildcard not recommended.
`ahmax`	Scalar numeric: major axis range or wildcard.
`ahmin`	Scalar numeric: semi-major axis range or wildcard.
`avert`	Scalar numeric: minor axis range or wildcard.
`fit`	Boolean: apply autofit.
`maxiter`	Scalar integer: Number of fitting iterations.
`vargsill`	Scalar numeric: sill to fit. Can be wildcard but not recommended.
`vario`	Numeric vector: variogram numbers in `expdata` to use.
`npairswt`	Boolean: use number of pairs weighting.
`invdistwt`	Boolean: use inverse distance weighting.
`minpairs`	Scalar integer: minimum number of pairs.
`fixhmaxvertanis`	Boolean: used fixed ahmax:avert anisotropy.
`hmaxvertanis`	Scalar numeric: fixed ahmax:avert anisotropy.
`fixhmaxhminanis`	Boolean: used fixed ahmax:ahmin anisotropy.
`hmaxhminanis`	Scalar numeric: fixed ahmax:ahmin anisotropy.

Wildcards are character strings of the form '?': unconstrained; 'min:max': constrained minimum and maximum; 'min:': constrained minimum; ':max': constrained maximum. The arguments c0, it, cc, azm, dip, tilt, ahmax, ahmin, and avert all support wildcards. The argument c0 does not support the '?' wildcard due to a possible bug in the Frotran program.

A data frame with discretized variogram models for display. The side effect of this function is a system file sysout) containing the variogram model parameters for the major, semi-major, and minor axes. In the case of a 2D variogram the semi-major and minor axes have the same parameters.

truemoid/rgslib documentation built on May 30, 2019, 2:14 p.m.