fgmCopula {copula}

Construction of a fgmCopula Class Object

Description

Constructs a multivariate multiparameter Farlie-Gumbel-Morgenstern copula class object with its corresponding parameters and dimension.

Usage

fgmCopula(param, dim = 2)

Arguments

param

a numeric vector specifying the parameter values.

dim

the dimension of the copula.

Value

A Farlie-Gumbel-Morgenstern copula object of class "fgmCopula".

Note

The verification of the validity of the parameter values is of high complexity and may not work for high dimensional copulas.

The random number generation needs to be properly tested, especially for dimensions higher than 2.

References

Nelsen, R. B. (2006), An introduction to Copulas, Springer, New York.

See Also

Copula, copula-class, fitCopula.

Examples

## a bivariate example
fgm.cop <- fgmCopula(1)
x <- rCopula(1000, fgm.cop)
cor(x, method = "kendall")
tau(fgm.cop)
cor(x, method = "spearman")
rho(fgm.cop)
persp  (fgm.cop, dCopula)
contour(fgm.cop, dCopula)

## a trivariate example with wrong parameter values
try(
 fgm2.cop <- fgmCopula(c(1,1,1,1), dim = 3)
) # Error: "Bad vector of parameters"

## a trivariate example with satisfactory parameter values
fgm2.cop <- fgmCopula(c(.2,-.2,-.4,.6), dim = 3)
fgm2.cop