Description

Functionality to numerically evaluate a scalar expression, give the values of its building blocks.

The input is a map which relates subtrees in the expression to numerical values. The evaluate function will then do a post-order iteration over the tree, collecting and combining the values thus obtained.

Currently needs the leaf nodes to have an entry in the subtree_values map; may be extended later to cover values of non-elementary subtrees.

If the input variables are 'a' NTensors, then at any stage...

#include <NEvaluator.hh>

Classes
class	VariableValues
	The expression will get evaluated for a range of values for each unknown sub-expression (variable). More...

Public Member Functions
	NEvaluator (const Ex &)

void	set_variable (const Ex &, const NTensor &val)
	Set the range of values which we want to insert into the indicated variable. More...

NTensor	evaluate ()
	Evaluate the expression, using the variable values set in `set_variable`. More...

void	find_variable_locations ()
	PRIVATE: More...

Public Attributes
std::map< Ex::iterator, NTensor, Ex::iterator_base_less >	subtree_values
	If we know the value of a subtree explicitly as a number, it is stored in this map. More...

std::map< Ex::iterator, Ex::iterator, Ex::iterator_base_less >	subtree_equalities
	If we know the value of a subtree is equal to another subtree (either in the same expression or another one), it is stored in the map below. More...

std::vector< VariableValues >	variable_values

Private Attributes
const Ex &	ex

Constructor & Destructor Documentation

◆ NEvaluator()

NEvaluator::NEvaluator ( const Ex & ex_ )

Member Function Documentation

◆ evaluate()

NTensor NEvaluator::evaluate ( )

Evaluate the expression, using the variable values set in set_variable.

◆ find_variable_locations()

void NEvaluator::find_variable_locations ( )

PRIVATE:

◆ set_variable()

void NEvaluator::set_variable	(	const Ex &	var,
		const NTensor &	val
	)

Set the range of values which we want to insert into the indicated variable.

Fills the map above.

Member Data Documentation

◆ ex

const Ex& cadabra::NEvaluator::ex

private

◆ subtree_equalities

std::map<Ex::iterator, Ex::iterator, Ex::iterator_base_less> cadabra::NEvaluator::subtree_equalities

If we know the value of a subtree is equal to another subtree (either in the same expression or another one), it is stored in the map below.

This then still needs a lookup in the subtree_values map.

◆ subtree_values

std::map<Ex::iterator, NTensor, Ex::iterator_base_less> cadabra::NEvaluator::subtree_values

If we know the value of a subtree explicitly as a number, it is stored in this map.

These are computed nodes.

◆ variable_values

std::vector<VariableValues> cadabra::NEvaluator::variable_values

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

core/NEvaluator.hh
core/NEvaluator.cc