HAC (version 0.1-1)

tree2str: String structure of a HAC

Description

The function prints the structure of HAC as string, so that the important characteristics of the copula can be identified.

Usage

tree2str(hac, theta = TRUE, digits = 3)

Arguments

hac

an object of the class hac.

theta

determines, whether the values of the dependency parameter(s) are printed (TRUE) or not (FALSE).

digits

a positive integer value specifying the number of digits of the dependency parameter(s).

Value

• a string of the class character.

See Also

plot.hac

Examples

# an object of the class hac is constructed
M = matrix(c(2, 0, 0, 0, 3, 4, 0, 0, ~X1 + X5, ~X2, ~X3, ~X4 + X6),
ncol = 4, byrow = TRUE)
g.model = hac(HAC_GUMBEL, M)

# the dependency parameters are returned within the curly brackets

# variables, which are hosted at the same node, are separated by a dot

# (X1.X5.X2)_{3} and (X3.X4.X6)_{4} are variables of the node with 
# dependency parameter 2
tree2str(g.model) # [1] "((X1.X5.X2)_{3}.(X3.X4.X6)_{4})_{2}"

# if theta = FALSE, only the structure of the variables is returned
tree2str(g.model, theta = FALSE) # [1] "((X1.X5.X2).(X3.X4.X6))"

# alternatively consider the following nested AC

# _{1} represents the initial node
# the first three variables are given by the subtree ((X4.X6.X2)_{3}.X3)_{2},
# X1 and X5
f.model = hac.full(type = HAC_CLAYTON, y = c(~X1 + X5, ~X3, ~X2, ~X4 + X6),
theta = c(1, 2, 3))
tree2str(f.model) # [1] "(((X4.X6.X2)_{3}.X3)_{2}.X1.X5)_{1}"