CDL descriptors: laplacian matrix

Laplacian matrix

Descriptor Category : topological
c++ entity: member

Description

A square AxA symmetric matrix, A being the number of vertices in the molecular graph, where the entries are defined as:
Li : delta(i) if i = j; -1 if {i,j} belongs to the edge list of the graph, 0 otherwise.
This matrix is part of the descriptors properties class. The selector for the property accessors is laplacian_matrixS.

Prototype

look example

Where defined

morpho/cdl/descriptors/properties/desc_mol_properties.hpp
the selector is defined in:
morpho/cdl/descriptors/properties/desc_mol_props_selectors.hpp

Namespace

morpho::cdl

Inherits from

No inheritance

Arguments

Example

// suppose you're streaming a mol format from the stdin:
// and you want to get a const reference to the laplacian matrix:
typedef desc_molecular_properties<>   desc_mol_props_t;
typedef boost::property<mol_propsS, molecular_properties<>,
  boost::property<descriptors_mol_propsS, desc_mol_props_t> > descr_props_t;
typedef molecule<double,descr_props_t>    M;
morpho::cdl::nail_juice<M>             j;
morpho::cdl::get_juice_from_stream(std::cin, j, 0, sdf_formatT());
M   mol(j);
const MolProperty<laplacian_matrixS,M>& LM = MolProperty<laplacian_matrixS,M>::get(mol);
for (int i=0; i<LM.size1(); ++i) {
  for (int j=0; j<LM.size2(); ++j) {
    std::cout << LM(i,j) << '\t';
  }
  std::cout << '\n';
}