practicalRangeCMB: Practical range for covariance function

In frycast/rcosmo: Cosmic Microwave Background Data Analysis

Practical range for covariance function

Description

This function computes the practical range for covariance functions on spheres. The function extends practicalRange from the package geoR to additional covariance models on spheres.

Usage

practicalRangeCMB(cov.model, phi, kappa = 0.5, correlation = 0.05, ...)

Arguments

cov.model	A type of the correlation function. Available choices are: "matern", "exponential","spherical", "powered.exponential", "cauchy", "gencauchy", "pure.nugget", "askey", "c2wendland", "c4wendland", "sinepower", "multiquadric".
phi	The range parameter as documented in covmodelCMB
kappa	A smoothness parameter of the correlation function.
correlation	A correlation threshold (default is 0.05)
...	other optimisation parameters

Details

The practical(effective) range for a covariance function is the distance at which a covariance function first time reaches the specified value correlation. For covariance functions on spheres the practical range does not exceed pi, the distance beyond which a covariance function is not defined. For the covariance functions "spherical", "askey", "c2wendland", "c4wendland" their practical ranges are equal to lengths of their support.

Value

Value of the practical range for the covariance function specified in covmodelCMB

References

geoR package, practicalRange, covmodelCMB

Examples

practicalRangeCMB(cov.model = "sinepower", phi = 0.1,  kappa = 0.5)
practicalRangeCMB(cov.model = "askey", phi = 0.1,  kappa = 0.5)

frycast/rcosmo documentation built on Oct. 11, 2022, 5:21 p.m.