CNode denotes a node in the computational graph. It stores the op-code, children, parents and other auxiliary information to evaluate the function and its derivative, check its properties etc. More...

#include <CNode.h>

Collaboration diagram for Minotaur::CNode:

[legend]

Public Member Functions
	CNode ()
	Default constructor.

	CNode (OpCode op, CNode **children, size_t num_child)
	: Construct a node from its children and an opcode More...

	CNode (OpCode op, CNode lchild, CNode rchild)
	: Construct a node from two children, left and right, and an opcode More...

	~CNode ()
	Destroy.

CNode *	clone () const
	Clone the node. Does not copy pointers to parents, children, etc.

void	addPar (CNode *node)
	Add a parent to a given node (a parent depends on the child in function evaluation). More...

void	changeChild (CNode out, CNode in)
	Replace one of the children of a given node by another node. More...

void	copyParChild (CNode out, std::map< const CNode , CNode * > *nmap) const
	Make copies of links pointing to parents and children to another node. Used in cloning the CGraph. More...

void	eval (const double x, int error)
	Evaluate the function at this node. More...

double	evalSingle (double x, int *error) const
	Evaluate the value of just this node based on the single value given as an input parameter. Ignores the values at the children nodes. Used by Transformer classes. Applicable only to nodes that require a single input (like OpUMinus, OpSqrt, etc) and not others (like OpSumList, OpPlus, OpMult, etc.) More...

FunctionType	findFType ()
	Find the type of the function (constant, linear, polynomial, etc.) based on the function type of children.

void	fwdGrad ()
	Calculate the derivative of the function at this node based on values and gradients of children nodes. Used in forward-mode gradient calculation.

bool	getB () const

double	getG () const

double	getH () const

size_t	getId () const

size_t	getIndex () const

CNode *	getL () const

double	getLb () const

CNode **	getListL () const

CNode **	getListR () const

OpCode	getOp () const

CQIter2 *	getParB () const

CNode *	getR () const

int	getTempI () const

FunctionType	getType () const

double	getUb () const

CNode *	getUPar () const

const Variable *	getV () const

double	getVal () const

void	grad (int *error)
	Push gradient values to children for reverse mode gradient evaluation. More...

size_t	numChild () const

size_t	numPar () const

void	propHessSpa ()
	Find whether child-nodes must participate in evaluation of the current column of the hessian-matrix. Sets values of internal flags and variables.

void	propHessSpa2 (CNodeRSet *nset)
	A variant of propHessSpa()

void	propBounds (bool is_inf, int error)
	Deduce and push new bounds to child-nodes based on bounds of this node. More...

void	hess (int *error)
	Reverse mode hessian evaluation. Hessian values are pushed to children nodes. More...

void	hess2 (CNodeRSet nset, int error)
	Reverse mode hessian evaluation with sparsity detection. Hessian values are pushed to children nodes. More...

void	setB (bool b)
	Set the boolean flag. More...

void	setBounds (double lb, double ub)
	Set lower and upper bounds on the node. More...

void	setDouble (double d)
	Set the constant double value (OpNum and OpInt). More...

void	setG (double g)
	Set the value of the derivative (reverse mode gradient) More...

void	setGi (double gi)
	Set the value of the derivative (forward mode gradient) More...

void	setH (double h)
	Set the value of the hessian. More...

void	setId (size_t i)
	Set the value of the node ID. More...

void	setIndex (size_t i)
	Set the value of the node index. More...

void	setL (CNode *n)
	Set the pointer to the left-most child. More...

void	setOp (OpCode op)
	Set the OpCode. More...

void	setR (CNode *n)
	Set the pointer to the right-most child. More...

void	setTempI (int i)
	Set the value of the temporary integer ti_. More...

void	setType (FunctionType t)
	Set the value of function type of the graph rooted at this node. More...

void	setVal (double v)
	Set the value of function at this node. More...

void	setV (VariablePtr v)
	Set the Variable at this node (for OpVar nodes) More...

void	updateBnd (int *error)
	Find bounds deduced from the bounds of children nodes and update lb_ and ub_. More...

void	write (std::ostream &out) const
	Print the function expression at current node only.

void	writeSubExp (std::ostream &out) const
	Print the function expression at current node and the sub-tree.

void	writeSubNl (std::stringstream &s, int *err) const
	Write the function expression in ASL's text format (reverse polish notation) for the current node and the sub-tree. More...

Protected Member Functions
void	propBounds_ (double lb, double ub, bool *is_inf)
	Change the current bounds of the function value at this node to new bounds only if the new bounds are tighter. Also checks whether the new bounds are inconsistent. More...

Protected Attributes
bool	b_

CNode **	child_
	Boolean flag used in finding hessian sparsity.

double	d_
	array of size numChild_ + 1. The last pointer is a null

FunctionType	fType_
	Constant double value in OpNum and OpInt nodes.

double	g_
	Function type of the graph rooted at this node.

double	gi_

double	h_

size_t	id_
	Value of the hessian.

size_t	index_
	Unique ID of a dependent node. 0 for independent nodes.

CNode *	l_
	Unique index of the node.

double	lb_
	Left child.

size_t	numChild_
	lower bound that a node can achieve

size_t	numPar_
	Number of children.

OpCode	op_
	Number of parents.

CQIter2 *	parB_
	Operation code.

CQIter2 *	parE_
	Pointer to the first parent (parents begin)

CNode *	r_
	Pointer to the last parent (parents end)

int	ti_
	Right child.

double	ub_

CNode *	uPar_
	upper bound that a node can achieve

const Variable *	v_

double	val_
	Pointer the variable in case it is OpVar.

Detailed Description

CNode denotes a node in the computational graph. It stores the op-code, children, parents and other auxiliary information to evaluate the function and its derivative, check its properties etc.

Constructor & Destructor Documentation

◆ CNode() [1/2]

CNode::CNode	(	OpCode	op,
		CNode **	children,
		size_t	num_child
	)

: Construct a node from its children and an opcode

Constructor with a specific opcode and children.

Parameters

[in]	op	Opcode of the new CNode
[in]	children	Pointer to an array of child nodes, can be null
[in]	Number	of children, can be zero or more

◆ CNode() [2/2]

CNode::CNode	(	OpCode	op,
		CNode *	lchild,
		CNode *	rchild
	)

: Construct a node from two children, left and right, and an opcode

Constructor with a specific opcode and two children.

Parameters

[in]	op	Opcode of the new CNode
[in]	lchild	Pointer to the left child node
[in]	rchild	Pointer to the right child node

Member Function Documentation

◆ addPar()

void CNode::addPar ( CNode * node )

Add a parent to a given node (a parent depends on the child in function evaluation).

\parm [in] Pointer to the parent node

◆ changeChild()

void CNode::changeChild	(	CNode *	out,
		CNode *	in
	)

Replace one of the children of a given node by another node.

Parameters

[in]	out	Pointer to the existing child node that will be replaced
[in]	in	Pointer to the new child node that will replace the existing child.

◆ copyParChild()

void CNode::copyParChild	(	CNode *	out,
		std::map< const CNode , CNode > *	nmap
	)		const

Make copies of links pointing to parents and children to another node. Used in cloning the CGraph.

Parameters

[in,out]	out	The node to which the links must be copied. This is the clone.
	[nmap]	in A map of nodes in of current CGraph to the nodes of new CGraph.

◆ eval()

void CNode::eval	(	const double *	x,
		int *	error
	)

Evaluate the function at this node.

Parameters

[in]	x	The point at which the CGraph containing this CNode is being evaluated. x is used only for nodes that have opcode OpVar. For all other nodes, the values of the children are used in evaluating the function.
[out]	error	Nonzero if some error occurs in evaluation e.g. log of a negative number, etc.

◆ evalSingle()

double CNode::evalSingle	(	double	x,
		int *	error
	)		const

Evaluate the value of just this node based on the single value given as an input parameter. Ignores the values at the children nodes. Used by Transformer classes. Applicable only to nodes that require a single input (like OpUMinus, OpSqrt, etc) and not others (like OpSumList, OpPlus, OpMult, etc.)

Parameters

[in]	x	The input argument for the function.
[out]	error	Nonzero if there is an error in evaluation like some IEEE exception.

Returns: The value of the function evaluated.

◆ getB()

bool Minotaur::CNode::getB ( ) const

inline

Returns: The value of the boolean flag.

◆ getG()

double Minotaur::CNode::getG ( ) const

inline

Returns: The value of the gradient value.

◆ getH()

double Minotaur::CNode::getH ( ) const

inline

Returns: The value of the hessian value at this node.

◆ getId()

size_t Minotaur::CNode::getId ( ) const

inline

Returns: The ID

◆ getIndex()

size_t Minotaur::CNode::getIndex ( ) const

inline

Returns: index of the node

◆ getL()

CNode * Minotaur::CNode::getL ( ) const

inline

Returns: The pointer to left child

◆ getLb()

double Minotaur::CNode::getLb ( ) const

inline

Returns: The lower bound

◆ getListL()

CNode ** Minotaur::CNode::getListL ( ) const

inline

Returns: Pointer to the beginning of array of pointers to children

◆ getListR()

CNode ** Minotaur::CNode::getListR ( ) const

inline

Returns: Pointer to the end of array of pointers to children

◆ getOp()

OpCode Minotaur::CNode::getOp ( ) const

inline

Returns: The opcode of this node.

◆ getR()

CNode * Minotaur::CNode::getR ( ) const

inline

Returns: The pointer to right child

◆ getType()

FunctionType Minotaur::CNode::getType ( ) const

inline

Returns: The stored function type (does not evaluate).

◆ getUb()

double Minotaur::CNode::getUb ( ) const

inline

Returns: The upper bound

◆ getUPar()

CNode * Minotaur::CNode::getUPar ( ) const

inline

Returns: The unique parent if any, otherwise return NULL

◆ getV()

const Variable * Minotaur::CNode::getV ( ) const

inline

Returns: Pointer to the variable if the node is OpVar, otherwise NULL

◆ getVal()

double Minotaur::CNode::getVal ( ) const

inline

Returns: The value of function stored at this node (does not evaluate)

◆ grad()

void CNode::grad ( int * error )

Push gradient values to children for reverse mode gradient evaluation.

Parameters

[out] error Nonzero if there is an error in evaluation.

◆ hess()

void CNode::hess ( int * error )

Reverse mode hessian evaluation. Hessian values are pushed to children nodes.

Parameters

[out] error Nonzero if some error is encountered in evaluation.

◆ hess2()

void CNode::hess2	(	CNodeRSet *	nset,
		int *	error
	)

Reverse mode hessian evaluation with sparsity detection. Hessian values are pushed to children nodes.

Parameters

[in,out]	nset	Children are added to nset if they participate in Hessian.
[out]	error	Nonzero if some error is encountered in evaluation.

◆ numChild()

size_t Minotaur::CNode::numChild ( ) const

inline

Returns: The number of children nodes.

◆ numPar()

size_t Minotaur::CNode::numPar ( ) const

inline

Returns: The number of parents

◆ propBounds()

void CNode::propBounds	(	bool *	is_inf,
		int *	error
	)

Deduce and push new bounds to child-nodes based on bounds of this node.

Parameters

[out]	is_inf	True if it detects inconsistency, i.e. infeasibility
[out]	error	Nonzero if some error is encountered in evaluation.

◆ propBounds_()

void CNode::propBounds_	(	double	lb,
		double	ub,
		bool *	is_inf
	)

protected

Change the current bounds of the function value at this node to new bounds only if the new bounds are tighter. Also checks whether the new bounds are inconsistent.

Current value of the expression based on the value of the children

Parameters

[in]	lb	New lower bound
[in]	ub	New upper bound
[out]	is_inf	Set to true if lb is more than ub after the update. Otherwise, remains unchanged.

◆ setB()

void Minotaur::CNode::setB ( bool b )

inline

Set the boolean flag.

Parameters

[in] b The flag.

◆ setBounds()

void Minotaur::CNode::setBounds	(	double	lb,
		double	ub
	)

inline

Set lower and upper bounds on the node.

Parameters

[in]	lb	Lower bound.
[in]	ub	Upper bound.

◆ setType()

void CNode::setType ( FunctionType t )

Set the value of function type of the graph rooted at this node.

Parameters

[in] t The type.

◆ setV()

void Minotaur::CNode::setV ( VariablePtr v )

inline

Set the Variable at this node (for OpVar nodes)

Parameters

[in] v The variable pointer.

◆ setVal()

void CNode::setVal ( double v )

Set the value of function at this node.

Parameters

[in] v The value.

◆ updateBnd()

void CNode::updateBnd ( int * error )

Find bounds deduced from the bounds of children nodes and update lb_ and ub_.

Parameters

[out] error Nonzero if some error is encountered in evaluating the bounds.

◆ writeSubNl()

void CNode::writeSubNl	(	std::stringstream &	s,
		int *	err
	)		const

Write the function expression in ASL's text format (reverse polish notation) for the current node and the sub-tree.

Parameters

[in]	s	stream to which the expression is appended
[out]	err	Nonzero if some error is encountered

Unique parent of this node. NULL if the node has multiple parents

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

/home/amahajan/tmp/minotaur-test/src/base/CNode.h
/home/amahajan/tmp/minotaur-test/src/base/CNode.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ CNode() [1/2]

◆ CNode() [2/2]

Member Function Documentation

◆ addPar()

◆ changeChild()

◆ copyParChild()

◆ eval()

◆ evalSingle()

◆ getB()

◆ getG()

◆ getH()

◆ getId()

◆ getIndex()

◆ getL()

◆ getLb()

◆ getListL()

◆ getListR()

◆ getOp()

◆ getR()

◆ getType()

◆ getUb()

◆ getUPar()

◆ getV()

◆ getVal()

◆ grad()

◆ hess()

◆ hess2()

◆ numChild()

◆ numPar()

◆ propBounds()

◆ propBounds_()

◆ setB()

◆ setBounds()

◆ setDouble()

◆ setG()

◆ setGi()

◆ setH()

◆ setId()

◆ setIndex()

◆ setL()

◆ setOp()

◆ setR()

◆ setTempI()

◆ setType()

◆ setV()

◆ setVal()

◆ updateBnd()

◆ writeSubNl()

Member Data Documentation

◆ gi_

◆ h_

◆ ub_

◆ v_