MeshGeoToolsLib::HeuristicSearchLength Class Reference

Detailed Description

HeuristicSearchLength implements a mesh dependent criterion for searching mesh nodes near a geometry. For this purpose it computes the average \(\mu\) and the standard deviation \(\sigma\) of edge length or node distance of mesh elements. The search length is set to \(\mu-2\sigma\). This strategy is useful for meshes with different sizes of elements.

Definition at line 30 of file HeuristicSearchLength.h.

#include <HeuristicSearchLength.h>

Inheritance diagram for MeshGeoToolsLib::HeuristicSearchLength:

Collaboration diagram for MeshGeoToolsLib::HeuristicSearchLength:

Public Types
enum class	LengthType { Edge , Node }
	Type of length to be sampled. More...

Public Member Functions
	HeuristicSearchLength (MeshLib::Mesh const &mesh, LengthType length_type=LengthType::Edge)
Public Member Functions inherited from MeshGeoToolsLib::SearchLength
	SearchLength (double search_length=1e-9)
	SearchLength (SearchLength const &)=default
SearchLength &	operator= (SearchLength const &)=default
virtual	~SearchLength ()=default
virtual double	getSearchLength () const

Private Attributes
MeshLib::Mesh const &	_mesh

Additional Inherited Members
Protected Attributes inherited from MeshGeoToolsLib::SearchLength
double	_search_length

Member Enumeration Documentation

LengthType

enum class MeshGeoToolsLib::HeuristicSearchLength::LengthType

strong

Type of length to be sampled.

Enumerator
Edge
Node	edge length of elements, which is recommended for meshes without nonlinear nodes distance between nodes

Definition at line 34 of file HeuristicSearchLength.h.

    {
        Edge, 
        Node  
    };

Constructor & Destructor Documentation

HeuristicSearchLength()

MeshGeoToolsLib::HeuristicSearchLength::HeuristicSearchLength ( MeshLib::Mesh const & mesh, LengthType length_type = LengthType::Edge )

explicit

Constructor

Parameters

mesh	mesh object
length_type	length type to be sampled

Definition at line 20 of file HeuristicSearchLength.cpp.

    : _mesh(mesh)
{
    double sum(0.0);
    double sum_of_sqr(0.0);  // total length of edges
 
    std::size_t n_sampling(0);  // total length of edges squared
    std::vector<MeshLib::Element*> const& elements(_mesh.getElements());
 
    if (length_type == LengthType::Edge)
    {
        for (auto element : elements)
        {
            std::size_t const n_edges(element->getNumberOfEdges());
            for (std::size_t k(0); k < n_edges; k++)
            {
                auto edge =
                    element->getEdge(k);  // allocation inside getEdge().
                double const len = edge->getContent();
                delete edge;
                sum += len;
                sum_of_sqr += len * len;
            }
            n_sampling += n_edges;
        }
    }
    else
    {
        for (const MeshLib::Element* e : elements)
        {
            auto const [min, max] =
                MeshLib::computeSqrNodeDistanceRange(*e, true);
            sum += std::sqrt(min);
            sum_of_sqr += min;
        }
        n_sampling = _mesh.getNumberOfElements();
    }
 
    const double mean(sum / n_sampling);
    const double variance((sum_of_sqr - (sum * sum) / n_sampling) /
                          (n_sampling - 1));
 
    // Set the search length for the case of non-positive variance (which can
    // happen due to numerics).
    _search_length = mean / 2;
 
    if (variance > 0)
    {
        if (variance < mean * mean / 4)
        {
            _search_length -= std::sqrt(variance);
        }
        else
        {
            _search_length = std::numeric_limits<double>::epsilon();
        }
    }
 
    DBUG(
        "[MeshNodeSearcher::MeshNodeSearcher] Calculated search length for "
        "mesh '{:s}' is {:f}.",
        _mesh.getName(), _search_length);
}

References _mesh, MeshGeoToolsLib::SearchLength::_search_length, MeshLib::computeSqrNodeDistanceRange(), DBUG(), and Edge.

Member Data Documentation

_mesh

MeshLib::Mesh const& MeshGeoToolsLib::HeuristicSearchLength::_mesh

private

Definition at line 49 of file HeuristicSearchLength.h.

Referenced by HeuristicSearchLength().

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The documentation for this class was generated from the following files:

• MeshGeoToolsLib/HeuristicSearchLength.h
• MeshGeoToolsLib/HeuristicSearchLength.cpp