B 3RcU@s:dZddlZddlmZddlmZddlZdddZdS)z Python functions for manipulating molecular graphs In theory much of the functionality in here should be migrating into the C/C++ codebase. N)Chem) DataStructsc Cs|}|dkrn|}dt|}|}t|dtj}d|d<xHtd|dD]6}d|t|||<||||}t||}qRW|ddd9<|S)aN calculates the characteristic polynomial for a molecular graph if mat is not passed in, the molecule's Weighted Adjacency Matrix will be used. The approach used is the Le Verrier-Faddeev-Frame method described in _Chemical Graph Theory, 2nd Edition_ by Nenad Trinajstic (CRC Press, 1992), pg 76. Ng?r)Z GetNumAtomsnumpyZidentityZzerosfloatrangeZtracedot) ZmolZmatZnAtomsAIZAnZresnZBnr 0lib/python3.7/site-packages/rdkit/Chem/Graphs.pyCharacteristicPolynomials r)N)__doc__rZrdkitrrtypesrr r r rs