The chemical theory module

Chemical theory class.

class hcga.features.chemical_theory.ChemicalTheory(graph=None)

Chemical theory class.

Here we implement the wiener and estrada indexes.

The Wiener index of a graph is the sum of the shortest-path distances between each pair of reachable nodes 1. For pairs of nodes in undirected graphs, only one orientation of the pair is counted.

The Estrada Index is a topological index of folding or 3D “compactness” 2.

References

1

Rouvray, Dennis H. “The rich legacy of half a century of the Wiener index.”,

Topology in Chemistry. Woodhead Publishing, 2002. 16-37.

2

E. Estrada, Characterization of 3D molecular structure, Chem. Phys. Lett. 319, 713 (2000).

Initialise a feature class.

Parameters

graph (Graph) – graph for initialisation, converted to given encoding

compute_features()

Main feature extraction function.

This function should be used by each specific feature class to add new features.