Cache that holds the values of 1D Lagrange polynomials. More...

#include <tsgCacheLagrange.hpp>

Public Member Functions
	CacheLagrange (int num_dimensions, const std::vector< int > &max_levels, const OneDimensionalWrapper &rule, const double x[])
	Constructor that takes into account a single canonical point x. More...

	~CacheLagrange ()=default
	Destructor, clear all used data.

T	getLagrange (int dimension, int level, int local) const
	Return the Lagrange cache for given dimension, level and offset local to the level.

Static Public Member Functions
static void	cacheLevel (int level, double x, const OneDimensionalWrapper &rule, T *cc)
	Computes the values of all Lagrange polynomials for the given level at the given x.

Protected Attributes
std::vector< std::vector< T > >	cache
	Stores the values of the Lagrange polynomias for each dimension and each level. More...

std::vector< int >	offsets
	Stores the offsets for each level within each dimension.

Detailed Description

template<typename T>
class TasGrid::CacheLagrange< T >

Cache that holds the values of 1D Lagrange polynomials.

Global grids have the most complex evaluation procedure, Lagrange polynomials have to be evaluated for each direction and each level, before the weighted sum can be accumulated to compute the values of the basis functions. The CacheLagrange class computes the values of the Lagrange polynomials and caches them for easy access.

Constructor & Destructor Documentation

◆ CacheLagrange()

template<typename T >

TasGrid::CacheLagrange< T >::CacheLagrange	(	int	num_dimensions,
		const std::vector< int > &	max_levels,
		const OneDimensionalWrapper &	rule,
		const double	x[]
	)

inline

Constructor that takes into account a single canonical point x.

The cache is constructed for each dimension and each level up to max_levels, the values of the Lagrange polynomials are computed in two passes resulting in O(n) operations.

num_dimensions is the number of dimensions to consider
max_levels indicates how many levels to consider in each direction, heavily anisotropic grids require only a few levels for the "less important" directions
rule is the wrapper of the Global grid that contains information about number of points per level and the actual nodes with the pre-computed Lagrange coefficients
holds the coordinates of the canonical point to cache

Member Data Documentation

◆ cache

template<typename T >

std::vector<std::vector<T> > TasGrid::CacheLagrange< T >::cache

protected

Stores the values of the Lagrange polynomias for each dimension and each level.

cache[i] corresponds to the i-th dimension. The i-th vector has the values of the Lagrange polynomials going level by level, so the value of the Lagrange polynomial for dimension i at level l with local offset j will be cache[i][ offsets[l] + j ]

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

SparseGrids/tsgCacheLagrange.hpp

Public Member Functions

Static Public Member Functions