slp::detail::Expression Struct Reference

An autodiff expression node. More...

#include </home/runner/work/allwpilib/allwpilib/wpimath/src/main/native/thirdparty/sleipnir/include/sleipnir/autodiff/expression.hpp>

Inheritance diagram for slp::detail::Expression:

Public Member Functions
constexpr	Expression ()=default
	Constructs a constant expression with a value of zero.
constexpr	Expression (double value)
	Constructs a nullary expression (an operator with no arguments).
constexpr	Expression (ExpressionPtr lhs)
	Constructs an unary expression (an operator with one argument).
constexpr	Expression (ExpressionPtr lhs, ExpressionPtr rhs)
	Constructs a binary expression (an operator with two arguments).
virtual	~Expression ()=default
constexpr bool	is_constant (double constant) const
	Returns true if the expression is the given constant.
virtual double	value (double lhs, double rhs) const =0
	Either nullary operator with no arguments, unary operator with one argument, or binary operator with two arguments.
virtual ExpressionType	type () const =0
	Returns the type of this expression (constant, linear, quadratic, or nonlinear).
virtual double	grad_l (double lhs, double rhs, double parent_adjoint) const
	Returns double adjoint of the left child expression.
virtual double	grad_r (double lhs, double rhs, double parent_adjoint) const
	Returns double adjoint of the right child expression.
virtual ExpressionPtr	grad_expr_l (const ExpressionPtr &lhs, const ExpressionPtr &rhs, const ExpressionPtr &parent_adjoint) const
	Returns Expression adjoint of the left child expression.
virtual ExpressionPtr	grad_expr_r (const ExpressionPtr &lhs, const ExpressionPtr &rhs, const ExpressionPtr &parent_adjoint) const
	Returns Expression adjoint of the right child expression.

Public Attributes
double	val = 0.0
	The value of the expression node.
double	adjoint = 0.0
	The adjoint of the expression node used during autodiff.
uint32_t	incoming_edges = 0
	Counts incoming edges for this node.
int32_t	col = -1
	This expression's column in a Jacobian, or -1 otherwise.
ExpressionPtr	adjoint_expr
	The adjoint of the expression node used during gradient expression tree generation.
uint32_t	ref_count = 0
	Reference count for intrusive shared pointer.
std::array< ExpressionPtr, 2 >	args {nullptr, nullptr}
	Expression arguments.

Friends
ExpressionPtr	operator* (const ExpressionPtr &lhs, const ExpressionPtr &rhs)
	Expression-Expression multiplication operator.
ExpressionPtr	operator/ (const ExpressionPtr &lhs, const ExpressionPtr &rhs)
	Expression-Expression division operator.
ExpressionPtr	operator+ (const ExpressionPtr &lhs, const ExpressionPtr &rhs)
	Expression-Expression addition operator.
ExpressionPtr	operator+= (ExpressionPtr &lhs, const ExpressionPtr &rhs)
	Expression-Expression compound addition operator.
ExpressionPtr	operator- (const ExpressionPtr &lhs, const ExpressionPtr &rhs)
	Expression-Expression subtraction operator.
ExpressionPtr	operator- (const ExpressionPtr &lhs)
	Unary minus operator.
ExpressionPtr	operator+ (const ExpressionPtr &lhs)
	Unary plus operator.

Detailed Description

An autodiff expression node.

Constructor & Destructor Documentation

Expression() [1/4]

slp::detail::Expression::Expression ( )

constexprdefault

Constructs a constant expression with a value of zero.

Expression() [2/4]

slp::detail::Expression::Expression ( double value )

inlineexplicitconstexpr

Constructs a nullary expression (an operator with no arguments).

Parameters

value

The expression value.

Expression() [3/4]

slp::detail::Expression::Expression ( ExpressionPtr lhs )

inlineexplicitconstexpr

Constructs an unary expression (an operator with one argument).

Parameters

lhs	Unary operator's operand.

Expression() [4/4]

slp::detail::Expression::Expression ( ExpressionPtr lhs, ExpressionPtr rhs )

inlineconstexpr

Constructs a binary expression (an operator with two arguments).

Parameters

lhs	Binary operator's left operand.
rhs	Binary operator's right operand.

~Expression()

virtual slp::detail::Expression::~Expression ( )

virtualdefault

Member Function Documentation

grad_expr_l()

virtual ExpressionPtr slp::detail::Expression::grad_expr_l ( const ExpressionPtr & lhs, const ExpressionPtr & rhs, const ExpressionPtr & parent_adjoint ) const

inlinevirtual

Returns Expression adjoint of the left child expression.

Parameters

lhs	Left argument to binary operator.
rhs	Right argument to binary operator.
parent_adjoint	Adjoint of parent expression.

Returns

The Expression adjoint of the left child expression.

Reimplemented in slp::detail::AbsExpression, slp::detail::AcosExpression, slp::detail::AsinExpression, slp::detail::Atan2Expression, slp::detail::AtanExpression, slp::detail::BinaryMinusExpression< T >, slp::detail::BinaryPlusExpression< T >, slp::detail::CosExpression, slp::detail::CoshExpression, slp::detail::DivExpression< T >, slp::detail::ErfExpression, slp::detail::ExpExpression, slp::detail::HypotExpression, slp::detail::Log10Expression, slp::detail::LogExpression, slp::detail::MultExpression< T >, slp::detail::PowExpression< T >, slp::detail::SignExpression, slp::detail::SinExpression, slp::detail::SinhExpression, slp::detail::SqrtExpression, slp::detail::TanExpression, slp::detail::TanhExpression, and slp::detail::UnaryMinusExpression< T >.

grad_expr_r()

virtual ExpressionPtr slp::detail::Expression::grad_expr_r ( const ExpressionPtr & lhs, const ExpressionPtr & rhs, const ExpressionPtr & parent_adjoint ) const

inlinevirtual

Returns Expression adjoint of the right child expression.

Parameters

lhs	Left argument to binary operator.
rhs	Right argument to binary operator.
parent_adjoint	Adjoint of parent expression.

Returns

The Expression adjoint of the right child expression.

Reimplemented in slp::detail::Atan2Expression, slp::detail::BinaryMinusExpression< T >, slp::detail::BinaryPlusExpression< T >, slp::detail::DivExpression< T >, slp::detail::HypotExpression, slp::detail::MultExpression< T >, and slp::detail::PowExpression< T >.

grad_l()

virtual double slp::detail::Expression::grad_l ( double lhs, double rhs, double parent_adjoint ) const

inlinevirtual

Returns double adjoint of the left child expression.

Parameters

lhs	Left argument to binary operator.
rhs	Right argument to binary operator.
parent_adjoint	Adjoint of parent expression.

Returns

The double adjoint of the left child expression.

Reimplemented in slp::detail::AbsExpression, slp::detail::AcosExpression, slp::detail::AsinExpression, slp::detail::Atan2Expression, slp::detail::AtanExpression, slp::detail::BinaryMinusExpression< T >, slp::detail::BinaryPlusExpression< T >, slp::detail::CosExpression, slp::detail::CoshExpression, slp::detail::DivExpression< T >, slp::detail::ErfExpression, slp::detail::ExpExpression, slp::detail::HypotExpression, slp::detail::Log10Expression, slp::detail::LogExpression, slp::detail::MultExpression< T >, slp::detail::PowExpression< T >, slp::detail::SignExpression, slp::detail::SinExpression, slp::detail::SinhExpression, slp::detail::SqrtExpression, slp::detail::TanExpression, slp::detail::TanhExpression, and slp::detail::UnaryMinusExpression< T >.

grad_r()

virtual double slp::detail::Expression::grad_r ( double lhs, double rhs, double parent_adjoint ) const

inlinevirtual

Returns double adjoint of the right child expression.

Parameters

lhs	Left argument to binary operator.
rhs	Right argument to binary operator.
parent_adjoint	Adjoint of parent expression.

Returns

The double adjoint of the right child expression.

Reimplemented in slp::detail::Atan2Expression, slp::detail::BinaryMinusExpression< T >, slp::detail::BinaryPlusExpression< T >, slp::detail::DivExpression< T >, slp::detail::HypotExpression, slp::detail::MultExpression< T >, and slp::detail::PowExpression< T >.

is_constant()

bool slp::detail::Expression::is_constant ( double constant ) const

inlineconstexpr

Returns true if the expression is the given constant.

Parameters

constant

The constant.

Returns

True if the expression is the given constant.

type()

virtual ExpressionType slp::detail::Expression::type ( ) const

pure virtual

Returns the type of this expression (constant, linear, quadratic, or nonlinear).

Returns

The type of this expression.

Implemented in slp::detail::AbsExpression, slp::detail::AcosExpression, slp::detail::AsinExpression, slp::detail::Atan2Expression, slp::detail::AtanExpression, slp::detail::BinaryMinusExpression< T >, slp::detail::BinaryPlusExpression< T >, slp::detail::ConstExpression, slp::detail::CosExpression, slp::detail::CoshExpression, slp::detail::DecisionVariableExpression, slp::detail::DivExpression< T >, slp::detail::ErfExpression, slp::detail::ExpExpression, slp::detail::HypotExpression, slp::detail::Log10Expression, slp::detail::LogExpression, slp::detail::MultExpression< T >, slp::detail::PowExpression< T >, slp::detail::SignExpression, slp::detail::SinExpression, slp::detail::SinhExpression, slp::detail::SqrtExpression, slp::detail::TanExpression, slp::detail::TanhExpression, and slp::detail::UnaryMinusExpression< T >.

value()

virtual double slp::detail::Expression::value ( double lhs, double rhs ) const

pure virtual

Either nullary operator with no arguments, unary operator with one argument, or binary operator with two arguments.

This operator is used to update the node's value.

Parameters

lhs	Left argument to binary operator.
rhs	Right argument to binary operator.

Returns

The node's value.

Implemented in slp::detail::AbsExpression, slp::detail::AcosExpression, slp::detail::AsinExpression, slp::detail::Atan2Expression, slp::detail::AtanExpression, slp::detail::BinaryMinusExpression< T >, slp::detail::BinaryPlusExpression< T >, slp::detail::ConstExpression, slp::detail::CosExpression, slp::detail::CoshExpression, slp::detail::DecisionVariableExpression, slp::detail::DivExpression< T >, slp::detail::ErfExpression, slp::detail::ExpExpression, slp::detail::HypotExpression, slp::detail::Log10Expression, slp::detail::LogExpression, slp::detail::MultExpression< T >, slp::detail::PowExpression< T >, slp::detail::SignExpression, slp::detail::SinExpression, slp::detail::SinhExpression, slp::detail::SqrtExpression, slp::detail::TanExpression, slp::detail::TanhExpression, and slp::detail::UnaryMinusExpression< T >.

Friends And Related Symbol Documentation

operator*

ExpressionPtr operator* ( const ExpressionPtr & lhs, const ExpressionPtr & rhs )

friend

Expression-Expression multiplication operator.

Parameters

lhs	Operator left-hand side.
rhs	Operator right-hand side.

operator+ [1/2]

ExpressionPtr operator+ ( const ExpressionPtr & lhs )

friend

Unary plus operator.

Parameters

lhs	Operand of unary plus.

operator+ [2/2]

ExpressionPtr operator+ ( const ExpressionPtr & lhs, const ExpressionPtr & rhs )

friend

Expression-Expression addition operator.

Parameters

lhs	Operator left-hand side.
rhs	Operator right-hand side.

operator+=

ExpressionPtr operator+= ( ExpressionPtr & lhs, const ExpressionPtr & rhs )

friend

Expression-Expression compound addition operator.

Parameters

lhs	Operator left-hand side.
rhs	Operator right-hand side.

operator- [1/2]

ExpressionPtr operator- ( const ExpressionPtr & lhs )

friend

Unary minus operator.

Parameters

lhs	Operand of unary minus.

operator- [2/2]

ExpressionPtr operator- ( const ExpressionPtr & lhs, const ExpressionPtr & rhs )

friend

Expression-Expression subtraction operator.

Parameters

lhs	Operator left-hand side.
rhs	Operator right-hand side.

operator/

ExpressionPtr operator/ ( const ExpressionPtr & lhs, const ExpressionPtr & rhs )

friend

Expression-Expression division operator.

Parameters

lhs	Operator left-hand side.
rhs	Operator right-hand side.

Member Data Documentation

adjoint

double slp::detail::Expression::adjoint = 0.0

The adjoint of the expression node used during autodiff.

adjoint_expr

ExpressionPtr slp::detail::Expression::adjoint_expr

The adjoint of the expression node used during gradient expression tree generation.

args

std::array<ExpressionPtr, 2> slp::detail::Expression::args {nullptr, nullptr}

Expression arguments.

col

int32_t slp::detail::Expression::col = -1

This expression's column in a Jacobian, or -1 otherwise.

incoming_edges

uint32_t slp::detail::Expression::incoming_edges = 0

Counts incoming edges for this node.

ref_count

uint32_t slp::detail::Expression::ref_count = 0

Reference count for intrusive shared pointer.

val

double slp::detail::Expression::val = 0.0

The value of the expression node.

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

• /home/runner/work/allwpilib/allwpilib/wpimath/src/main/native/thirdparty/sleipnir/include/sleipnir/autodiff/expression.hpp