ExpressionAdd Class Reference

Detailed Description

Symbolic expression representing an addition which is a sum of products.

\[ c_0 + \sum c_i * e_i \]

where \( c_i \) is a constant and \( e_i \) is a symbolic expression.

Internally this class maintains a member variable constant_ to represent \( c_0 \) and another member variable expr_to_coeff_map_ to represent a mapping from an expression \( e_i \) to its coefficient \( c_i \) of double.

#include <drake/common/symbolic/expression/expression_cell.h>

Public Member Functions
	ExpressionAdd (double constant, std::map< Expression, double > expr_to_coeff_map)
	Constructs ExpressionAdd from constant_term and term_to_coeff_map.
	~ExpressionAdd () override
void	HashAppendDetail (DelegatingHasher *) const override
	Sends all hash-relevant bytes for this ExpressionCell type into the given hasher, per the hash_append generic hashing concept – except for get_kind(), because Expression already sends that.
Variables	GetVariables () const override
	Collects variables in expression.
bool	EqualTo (const ExpressionCell &e) const override
	Checks structural equality.
bool	Less (const ExpressionCell &e) const override
	Provides lexicographical ordering between expressions.
double	Evaluate (const Environment &env) const override
	Evaluates under a given environment (by default, an empty environment).
Expression	Expand () const override
	Expands out products and positive integer powers in expression.
Expression	EvaluatePartial (const Environment &env) const override
	Returns an Expression obtained by replacing all occurrences of the variables in env in the current expression cell with the corresponding values in env.
Expression	Substitute (const Substitution &s) const override
	Returns an Expression obtained by replacing all occurrences of the variables in s in the current expression cell with the corresponding expressions in s.
Expression	Differentiate (const Variable &x) const override
	Differentiates this symbolic expression with respect to the variable var.
std::ostream &	Display (std::ostream &os) const override
	Outputs string representation of expression into output stream os.
double	get_constant () const
	Returns the constant.
const std::map< Expression, double > &	get_expr_to_coeff_map () const
	Returns map from an expression to its coefficient.
Public Member Functions inherited from ExpressionCell
virtual	~ExpressionCell ()
std::atomic< int > &	use_count () const
	Returns the intrusive use count (ala boost::intrusive_ptr).
ExpressionKind	get_kind () const
	Returns expression kind.
bool	is_polynomial () const
	Checks if this symbolic expression is convertible to Polynomial.
bool	is_expanded () const
	Checks if this symbolic expression is already expanded.
void	set_expanded ()
	Sets this symbolic expression as already expanded.
	ExpressionCell (const ExpressionCell &)=delete
ExpressionCell &	operator= (const ExpressionCell &)=delete
	ExpressionCell (ExpressionCell &&)=delete
ExpressionCell &	operator= (ExpressionCell &&)=delete

Additional Inherited Members
Protected Member Functions inherited from ExpressionCell
	ExpressionCell (ExpressionKind k, bool is_poly, bool is_expanded)
	Constructs ExpressionCell of kind k with is_poly and is_expanded, with a use_count of zero.

Constructor & Destructor Documentation

ExpressionAdd()

ExpressionAdd	(	double	constant,
		std::map< Expression, double >	expr_to_coeff_map )

Constructs ExpressionAdd from constant_term and term_to_coeff_map.

~ExpressionAdd()

~ExpressionAdd ( )

override

Member Function Documentation

Differentiate()

Expression Differentiate ( const Variable & x ) const

nodiscardoverridevirtual

Differentiates this symbolic expression with respect to the variable var.

Exceptions

std::exception

if it is not differentiable.

Implements ExpressionCell.

Display()

std::ostream & Display ( std::ostream & os ) const

overridevirtual

Outputs string representation of expression into output stream os.

Implements ExpressionCell.

EqualTo()

bool EqualTo ( const ExpressionCell & c ) const

nodiscardoverridevirtual

Checks structural equality.

Implements ExpressionCell.

Evaluate()

double Evaluate ( const Environment & env ) const

nodiscardoverridevirtual

Evaluates under a given environment (by default, an empty environment).

Exceptions

std::exception

if NaN is detected during evaluation.

Implements ExpressionCell.

EvaluatePartial()

Expression EvaluatePartial ( const Environment & env ) const

nodiscardoverridevirtual

Returns an Expression obtained by replacing all occurrences of the variables in env in the current expression cell with the corresponding values in env.

Exceptions

std::exception

if NaN is detected during substitution.

Implements ExpressionCell.

Expand()

Expression Expand ( ) const

nodiscardoverridevirtual

Expands out products and positive integer powers in expression.

Exceptions

std::exception

if NaN is detected during expansion.

Implements ExpressionCell.

get_constant()

double get_constant ( ) const

nodiscard

Returns the constant.

get_expr_to_coeff_map()

const std::map< Expression, double > & get_expr_to_coeff_map ( ) const

nodiscard

Returns map from an expression to its coefficient.

GetVariables()

Variables GetVariables ( ) const

nodiscardoverridevirtual

Collects variables in expression.

Implements ExpressionCell.

HashAppendDetail()

void HashAppendDetail ( DelegatingHasher * ) const

overridevirtual

Sends all hash-relevant bytes for this ExpressionCell type into the given hasher, per the hash_append generic hashing concept – except for get_kind(), because Expression already sends that.

Implements ExpressionCell.

Less()

bool Less ( const ExpressionCell & c ) const

nodiscardoverridevirtual

Provides lexicographical ordering between expressions.

Implements ExpressionCell.

Substitute()

Expression Substitute ( const Substitution & s ) const

nodiscardoverridevirtual

Returns an Expression obtained by replacing all occurrences of the variables in s in the current expression cell with the corresponding expressions in s.

Exceptions

std::exception

if NaN is detected during substitution.

Implements ExpressionCell.

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

• drake/common/symbolic/expression/expression_cell.h