slp::detail::Expression< Scalar_ > Struct Template Reference

#include <sleipnir/autodiff/expression.hpp>

Public Types
using	Scalar = Scalar_

Public Member Functions
constexpr	Expression ()=default
constexpr	Expression (Scalar value)
constexpr	Expression (ExpressionPtr< Scalar > lhs)
constexpr	Expression (ExpressionPtr< Scalar > lhs, ExpressionPtr< Scalar > rhs)
constexpr bool	is_constant (Scalar constant) const
virtual Scalar	value (Scalar lhs, Scalar rhs) const =0
virtual ExpressionType	type () const =0
virtual Scalar	grad_l (Scalar lhs, Scalar rhs, Scalar parent_adjoint) const
virtual Scalar	grad_r (Scalar lhs, Scalar rhs, Scalar parent_adjoint) const
virtual ExpressionPtr< Scalar >	grad_expr_l (const ExpressionPtr< Scalar > &lhs, const ExpressionPtr< Scalar > &rhs, const ExpressionPtr< Scalar > &parent_adjoint) const
virtual ExpressionPtr< Scalar >	grad_expr_r (const ExpressionPtr< Scalar > &lhs, const ExpressionPtr< Scalar > &rhs, const ExpressionPtr< Scalar > &parent_adjoint) const

Public Attributes
Scalar	val {0}
	The value of the expression node.
Scalar	adjoint {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< Scalar >	adjoint_expr
uint32_t	ref_count = 0
	Reference count for intrusive shared pointer.
std::array< ExpressionPtr< Scalar >, 2 >	args {nullptr, nullptr}
	Expression arguments.

Friends
ExpressionPtr< Scalar >	operator* (const ExpressionPtr< Scalar > &lhs, const ExpressionPtr< Scalar > &rhs)
ExpressionPtr< Scalar >	operator/ (const ExpressionPtr< Scalar > &lhs, const ExpressionPtr< Scalar > &rhs)
ExpressionPtr< Scalar >	operator+ (const ExpressionPtr< Scalar > &lhs, const ExpressionPtr< Scalar > &rhs)
ExpressionPtr< Scalar >	operator+= (ExpressionPtr< Scalar > &lhs, const ExpressionPtr< Scalar > &rhs)
ExpressionPtr< Scalar >	operator- (const ExpressionPtr< Scalar > &lhs, const ExpressionPtr< Scalar > &rhs)
ExpressionPtr< Scalar >	operator- (const ExpressionPtr< Scalar > &lhs)
ExpressionPtr< Scalar >	operator+ (const ExpressionPtr< Scalar > &lhs)

Detailed Description

template<typename Scalar_>
struct slp::detail::Expression< Scalar_ >

An autodiff expression node.

Template Parameters

Scalar

Scalar type.

Member Typedef Documentation

Scalar

template<typename Scalar_ >

using slp::detail::Expression< Scalar_ >::Scalar = Scalar_

Scalar type alias.

Constructor & Destructor Documentation

Expression() [1/4]

template<typename Scalar_ >

constexpr slp::detail::Expression< Scalar_ >::Expression ( )

constexprdefault

Constructs a constant expression with a value of zero.

Expression() [2/4]

template<typename Scalar_ >

constexpr slp::detail::Expression< Scalar_ >::Expression ( Scalar  value )

inlineexplicitconstexpr

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

Parameters

value

The expression value.

Expression() [3/4]

template<typename Scalar_ >

constexpr slp::detail::Expression< Scalar_ >::Expression ( ExpressionPtr< Scalar >  lhs )

inlineexplicitconstexpr

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

Parameters

lhs	Unary operator's operand.

Expression() [4/4]

template<typename Scalar_ >

constexpr slp::detail::Expression< Scalar_ >::Expression ( ExpressionPtr< Scalar >  lhs, ExpressionPtr< Scalar >  rhs  )

inlineconstexpr

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

Parameters

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

Member Function Documentation

grad_expr_l()

template<typename Scalar_ >

virtual ExpressionPtr< Scalar > slp::detail::Expression< Scalar_ >::grad_expr_l ( const ExpressionPtr< Scalar > &  lhs, const ExpressionPtr< Scalar > &  rhs, const ExpressionPtr< Scalar > &  parent_adjoint  ) const

inlinevirtual

Returns ∂/∂l as an Expression.

Parameters

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

Returns

∂/∂l as an Expression.

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

grad_expr_r()

template<typename Scalar_ >

virtual ExpressionPtr< Scalar > slp::detail::Expression< Scalar_ >::grad_expr_r ( const ExpressionPtr< Scalar > &  lhs, const ExpressionPtr< Scalar > &  rhs, const ExpressionPtr< Scalar > &  parent_adjoint  ) const

inlinevirtual

Returns ∂/∂r as an Expression.

Parameters

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

Returns

∂/∂r as an Expression.

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

grad_l()

template<typename Scalar_ >

virtual Scalar slp::detail::Expression< Scalar_ >::grad_l ( Scalar  lhs, Scalar  rhs, Scalar  parent_adjoint  ) const

inlinevirtual

Returns ∂/∂l as a Scalar.

Parameters

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

Returns

∂/∂l as a Scalar.

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

grad_r()

template<typename Scalar_ >

virtual Scalar slp::detail::Expression< Scalar_ >::grad_r ( Scalar  lhs, Scalar  rhs, Scalar  parent_adjoint  ) const

inlinevirtual

Returns ∂/∂r as a Scalar.

Parameters

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

Returns

∂/∂r as a Scalar.

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

is_constant()

template<typename Scalar_ >

constexpr bool slp::detail::Expression< Scalar_ >::is_constant ( Scalar  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()

template<typename Scalar_ >

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

value()

template<typename Scalar_ >

virtual Scalar slp::detail::Expression< Scalar_ >::value ( Scalar  lhs, Scalar  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::PowExpression< Scalar, T >, slp::detail::BinaryMinusExpression< Scalar, T >, slp::detail::BinaryPlusExpression< Scalar, T >, slp::detail::DivExpression< Scalar, T >, slp::detail::MultExpression< Scalar, T >, slp::detail::UnaryMinusExpression< Scalar, T >, slp::detail::HypotExpression< Scalar >, slp::detail::CbrtExpression< Scalar >, slp::detail::AbsExpression< Scalar >, slp::detail::AcosExpression< Scalar >, slp::detail::AsinExpression< Scalar >, slp::detail::AtanExpression< Scalar >, slp::detail::CosExpression< Scalar >, slp::detail::CoshExpression< Scalar >, slp::detail::ErfExpression< Scalar >, slp::detail::ExpExpression< Scalar >, slp::detail::LogExpression< Scalar >, slp::detail::Log10Expression< Scalar >, slp::detail::SignExpression< Scalar >, slp::detail::SinExpression< Scalar >, slp::detail::SinhExpression< Scalar >, slp::detail::SqrtExpression< Scalar >, slp::detail::TanExpression< Scalar >, slp::detail::TanhExpression< Scalar >, slp::detail::Atan2Expression< Scalar >, slp::detail::ConstExpression< Scalar >, and slp::detail::DecisionVariableExpression< Scalar >.

Friends And Related Symbol Documentation

operator*

template<typename Scalar_ >

ExpressionPtr< Scalar > operator* ( const ExpressionPtr< Scalar > &  lhs, const ExpressionPtr< Scalar > &  rhs  )

friend

Expression-Expression multiplication operator.

Parameters

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

operator+ [1/2]

template<typename Scalar_ >

ExpressionPtr< Scalar > operator+ ( const ExpressionPtr< Scalar > &  lhs )

friend

Unary plus operator.

Parameters

lhs	Operand of unary plus.

operator+ [2/2]

template<typename Scalar_ >

ExpressionPtr< Scalar > operator+ ( const ExpressionPtr< Scalar > &  lhs, const ExpressionPtr< Scalar > &  rhs  )

friend

Expression-Expression addition operator.

Parameters

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

operator+=

template<typename Scalar_ >

ExpressionPtr< Scalar > operator+= ( ExpressionPtr< Scalar > &  lhs, const ExpressionPtr< Scalar > &  rhs  )

friend

Expression-Expression compound addition operator.

Parameters

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

operator- [1/2]

template<typename Scalar_ >

ExpressionPtr< Scalar > operator- ( const ExpressionPtr< Scalar > &  lhs )

friend

Unary minus operator.

Parameters

lhs	Operand of unary minus.

operator- [2/2]

template<typename Scalar_ >

ExpressionPtr< Scalar > operator- ( const ExpressionPtr< Scalar > &  lhs, const ExpressionPtr< Scalar > &  rhs  )

friend

Expression-Expression subtraction operator.

Parameters

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

operator/

template<typename Scalar_ >

ExpressionPtr< Scalar > operator/ ( const ExpressionPtr< Scalar > &  lhs, const ExpressionPtr< Scalar > &  rhs  )

friend

Expression-Expression division operator.

Parameters

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

Member Data Documentation

adjoint_expr

template<typename Scalar_ >

ExpressionPtr<Scalar> slp::detail::Expression< Scalar_ >::adjoint_expr

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

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

• include/sleipnir/autodiff/expression.hpp