tree2str: String structure of HAC

In HAC: Estimation, Simulation and Visualization of Hierarchical Archimedean Copulae (HAC)

String structure of 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 = 2)

Arguments

hac	an object of the class hac.
theta	boolean. Determines, whether the values of the dependency parameter(s) are printed (TRUE) or not (FALSE).
digits	a non-negative integer value specifying the number of digits of the dependency parameter(s).

Value

a string of the class character.

See Also

plot.hac

Examples

# construct a hac object
tree = list(list("X1", "X5", "X2", 3), list("X3", "X4", "X6", 4), 2)
model = hac(type = 1, tree = tree)

# the parameters are returned within the curly brackets
# variables nested at the same node are separated by a dot

tree2str(model) # [1] "((X1.X5.X2)_{3}.(X3.X4.X6)_{4})_{2}"

# (X1.X5.X2)_{3} and (X3.X4.X6)_{4} are the two variables nested at the
# initial node with dependency parameter 2

tree2str(model, theta = FALSE) # [1] "((X1.X5.X2).(X3.X4.X6))"

# if theta = FALSE, only the structure of the variables is returned

# alternatively consider the following nested AC

tree = list("X1", list("X5", "X2", 3), list("X3", "X4", "X6", 4), 1.01)
model = hac(type = 1, tree = tree)

tree2str(model) # [1] "(X1.(X5.X2)_{3}.(X3.X4.X6)_{4})_{1.01}"

# _{1.01} represents the initial node
# the first three variables are given by the subtrees (X3.X4.X6)_{4},
# (X5.X2)_{3} and X1

HAC documentation built on Sept. 17, 2024, 1:06 a.m.