DDMParams

ferreus_rbf.config.DDMParams(leaf_threshold, overlap_quota, coarse_ratio, coarse_threshold)

Parameters controlling construction of the domain decomposition hierarchy.

ferreus_rbf employs a domain decomposition preconditioner to accelerate convergence of the iterative RBF solver. The algorithm recursively partitions the input point cloud into a hierarchy of overlapping subdomains, within which local RBF systems are solved directly and combined to form a global preconditioner.

This class defines the key thresholds and ratios governing how that hierarchy is generated - for example, the number of points permitted per leaf domain, how much overlap occurs between neighboring subdomains, and the scale at which coarse levels are formed.

Intended Usage

This configuration is part of the public API mainly for developers and advanced users who wish to experiment with or tune the decomposition process. For example, increasing subdomain overlap and coarse ratio can improve convergence, but at the cost of higher memory usage. In general, the default values have been selected to provide a robust trade-off between memory usage and solver performance across a wide range of problem sizes.

Default values when DDMParams isn't provided to RBFInterpolator:

• leaf_threshold: 1024
• overlap_quota: 0.5
• coarse_ratio: 0.125
• coarse_threshold: 4096

Parameters:

Name	Type	Description	Default
leaf_threshold	int	Target maximum number of points (internal + overlapping) within a leaf domain.	required
overlap_quota	float	Overlap fraction. Larger fraction will add more overlapping points to each leaf domain.	required
coarse_ratio	float	Fraction of internal points per leaf promoted to the next coarser level.	required
coarse_threshold	int	Maximum number of points in the coarsest level.	required