narumiKatayama: Narumi-Katayama index

Description

This method calculates the Narumi-Katayama index.

Usage

narumiKatayama(g, deg = NULL)

Arguments

a graph as a graphNEL object.

deg

the degree of each node of g. Will be automatically calculated if not supplied.

Value

integer value.

References

H. Narumi and M. Katayama: Simple topological index. A newly devised index characterizing the topological nature of structural isomers of saturated hydrocarbons. Mem. Fac. Engin. Hokkaido Univ., 16:209, 1984

Examples

Run this code


library(graph)
set.seed(123)
g <- randomEGraph(as.character(1:9), 0.5)

# optional: pre-calculate degree of nodes in g
vec.degree <- graph::degree(g)

narumiKatayama(g, vec.degree)