copBasic (version 1.7.1)

gridCOP: Compute a Copula on a Grid

Description

Compute a grid of copula values. This function has the primary intention of supporting 3-D renderings or 2-D images of the copulatic surface. Users should be aware of the origin convention of various plotting mechanisms available to them. By convention copulatic surface start in lower left corner for $u = v = 0$ but matrix conventions (or at least how some functions plot matrices) start with the origin in the upper left.

Usage

gridCOP(cop=NULL, para=NULL, delta=0.05, transpose=TRUE, ...)

Arguments

cop

A copula function;

para

Vector of parameters or other data structure, if needed, to pass to the copula;

delta

The $\Delta u = \Delta v$ of the grid edges;

transpose

A logical to transpose the returned grid. This is needed if functions such as image() in Rare to be used for visualization (see last Example with composite2COP); and

...

Additional arguments to pass.

Value

• The values for $\mathbf{C}(u,v)$ are returned as a grid.

See Also

EMPIRcopdf

Examples

image(gridCOP(cop=PSP))
# See this composite copula also used in densityCOPplot().
para <- list(alpha=0.15, beta=0.90, kappa=0.06, gamma=0.96,
             cop1=GHcop, cop2=PLACKETTcop, para1=5.5, para2=0.07)
GR <- gridCOP(cop=composite2COP, para=para, delta=0.005)
image(GR, col=terrain.colors(20))