covarianceStructure3D-class: Covariance structure
In italo-goncalves/geomod3D: Implicit 3D Geological Modeling and Geostatistics

Representation of one structure in a spatial continuity model.

covarianceStructure3D(type = c("gaussian", "exponential", "spherical",
  "cubic", "matern1", "matern2", "cauchy"), contribution, maxrange,
  midrange = maxrange, minrange = midrange, azimuth = 0, dip = 0,
  rake = 0, power = 1)

type: The type of covariance function represented.
contribution: The variance associated with this structure.
maxrange,midrange,minrange: The structure's range in three orthogonal directions, or the three semi-axes of the covariance ellipsoid.
azimuth,dip,rake: Orientation of the covariance ellipsoid in geological coordinates.
power: The power parameter for the covariance functions that feature one.