Geometric clustering

A geometric clustering is a hierarchical partition of the underlying geometry on which the kernel matrix is defined. See htool::ClusterTreeBuilder::create_cluster_tree() for more information about the available parameters to customize htool::Cluster construction.

Available customizations

To create geometric clustering with htool::ClusterTreeBuilder, two types of strategies allow customization of the algorithm defining \(n_{\mathrm{children}}\) children of a cluster node:

1. Computation of the main directions for a given cluster node. Available strategies are:

   • htool::ComputeLargestExtent

   • htool::ComputeBoundingBox

2. Splitting position of a cluster node along a given direction. Available strategies are

   • htool::RegularSplitting

   • htool::GeometricSplitting

Strategies can be used to define a htool::Partitioning that can be given to htool::ClusterTreeBuilder via htool::ClusterTreeBuilder::set_partitioning_strategy().

In any case, htool::Partitioning will compute the main direction of the current cluster, using the first strategy, and split the current cluster \(n_{\mathrm{children}}\) times orthogonally to this direction using the second strategy.

See here for more advanced customization.

Visualisation

The geometric clustering can be exported to a file using htool::save_clustered_geometry().