gsi.EVario3D: Empirical variogram or covariance function in 3D

In gmGeostats: Geostatistics for Compositional Analysis

Empirical variogram or covariance function in 3D

Description

compute the empirical variogram or covariance function in a 3D case study

Usage

gsi.EVario3D(
  X,
  Z,
  Ff = rep(1, nrow(X)),
  maxdist = max(dist(X[sample(nrow(X), min(nrow(X), 1000)), ]))/2,
  lagNr = 15,
  lags = seq(from = 0, to = maxdist, length.out = lagNr + 1),
  dirvecs = t(c(1, 0, 0)),
  angtol = 90,
  maxbreadth = Inf,
  minpairs = 10,
  cov = FALSE
)

Arguments

X	matrix of Nx3 columns with the geographic coordinates
Z	matrix or data.frame of data with dimension (N,Dv)
Ff	for variogram, matrix of basis functions with nrow(Ff)=N (can be a N-vector of 1s; should include the vector of 1s!!); for covariance function, a (N,Dv)-matrix or a Dv-vector giving the mean values
maxdist	maximum lag distance to consider
lagNr	number of lags to consider
lags	if maxdist and lagNr are not specified, either: (a) a matrix of 2 columns giving minimal and maximal lag distance defining the lag classes to consider, or (b) a vector of lag breaks
dirvecs	matrix which rows are the director vectors along which variograms will be computed (these will be normalized!)
angtol	scalar, angular tolerance applied (in degrees; defaults to 90??, ie. isotropic)
maxbreadth	maximal breadth (in lag units) orthogonal to the lag direction (defaults to Inf, ie. not used)
minpairs	minimal number of pairs falling in each class to consider the calculation sufficient; defaults to 10
cov	boolean, is covariance (TRUE) or variogram (FALSE) desired? defaults to variogram

Value

An empirical variogram for the provided data. NOTE: avoid using directly gsi.* functions! They represent either internal functions, or preliminary, not fully-tested functions. Use variogram instead.

See Also

Other gmEVario functions: as.gmEVario.gstatVariogram(), gsi.EVario2D(), ndirections(), plot.gmEVario(), variogramModelPlot()

gmGeostats documentation built on April 18, 2023, 5:08 p.m.