Nektar::LibUtilities::AnalyticExpressionEvaluator Class Reference

This class defines evaluator of analytic (symbolic) mathematical expressions. Expressions are allowed to depend on a number of spatial-time variables and parameters. Pre-processing and evaluation stages are split. At evaluation stage one specifies values for each variable, resulting expression value is returned. Vectorized evaluator (evaluate expression at a set of points) is available. More...

#include <AnalyticExpressionEvaluator.hpp>

Collaboration diagram for Nektar::LibUtilities::AnalyticExpressionEvaluator:

Classes
class	AnalyticExpression
struct	CopyState
struct	EvalAbs
struct	EvalAcos
struct	EvalAng
struct	EvalAsin
struct	EvalAtan
struct	EvalAtan2
struct	EvalAWGN
struct	EvalBessel
struct	EvalCeil
struct	EvalCos
struct	EvalCosh
struct	EvalDiv
struct	EvalExp
struct	EvalFabs
struct	EvalFloor
struct	EvalLog
struct	EvalLog10
struct	EvalLogicalEqual
struct	EvalLogicalGeq
struct	EvalLogicalGreater
struct	EvalLogicalLeq
struct	EvalLogicalLess
struct	EvalMul
struct	EvalNeg
struct	EvalPow
struct	EvalRad
struct	EvalSign
struct	EvalSin
struct	EvalSinh
struct	EvalSqrt
struct	EvalSub
struct	EvalSum
struct	EvalTan
struct	EvalTanh
struct	EvaluationStep
	Function objects (functors) More...
struct	StoreConst
struct	StorePrm
struct	StoreVar

Public Types
typedef std::map< std::string, int >	VariableMap
typedef std::map< std::string, int >	ConstantMap
typedef std::map< std::string, int >	ParameterMap
typedef std::map< std::string, int >	ExpressionMap
typedef std::map< std::string, int >	FunctionNameMap
typedef std::vector < EvaluationStep * >	ExecutionStack
typedef std::pair< bool, NekDouble >	PrecomputedValue
typedef NekDouble(*	OneArgFunc )(NekDouble)
typedef NekDouble(*	TwoArgFunc )(NekDouble, NekDouble)
typedef boost_spirit::tree_parse_info < std::string::const_iterator, boost_spirit::node_val_data_factory < NekDouble > >	ParsedTreeInfo
typedef boost_spirit::tree_match < std::string::const_iterator, boost_spirit::node_val_data_factory < NekDouble > >::tree_iterator	ParsedTreeIterator
typedef std::vector< const Array< OneD, const NekDouble > * >	VariableArray
typedef boost::mt19937	RandomGeneratorType

Public Member Functions
	AnalyticExpressionEvaluator (void)
	Initializes the evaluator to a state where it is ready to accept input from the DefineFunction function. More...
	~AnalyticExpressionEvaluator (void)
	Destroys the execution stack. More...
void	SetRandomSeed (unsigned int seed=123u)
void	AddConstants (std::map< std::string, NekDouble > const &constants)
	Constants are evaluated and inserted into the function at the time it is parsed when calling the DefineFunction function. After parsing, if a constant is changed, it will not be reflected in the function when Evaluate is called. This also means that if a function with an unknown constant is added, and then the constant is added, the function will not see the added constant and through an exception. This function will add all of the constants in the map argument to the global internal constants. If a constant was already loaded previously, it will throw an exception stating which constants in the map had this issue. It will add all of the constants it can and output the constants it couldn't add in the string exception. More...
int	AddConstant (std::string const &name, NekDouble value)
	This function behaves in the same way as AddConstants, but it only adds one constant at a time. If the constant existed previously, an exception will be thrown stating the fact. If it did not exist previously, it will be added to the global constants and will be used the next time DefineFunction is called. More...
NekDouble	GetConstant (std::string const &name)
	If a constant with the specified name exists, it returns the NekDouble value that the constant stores. If the constant doesn't exist, it throws an exception. More...
void	SetParameters (std::map< std::string, NekDouble > const &params)
	Parameters are like constants, but they are inserted into the function at the time Evaluate is called instead of when the function is parsed. This function can be called at any time, and it will take effect in the next call to Evaluate. This function will delete all of the parameters, and replace all of them with only the ones in the map argument. More...
void	SetParameter (std::string const &name, NekDouble value)
	This function behaves in the same way as SetParameters, but it only adds one parameter and it does not delete the others. If the parameter existed previously, it will be overridden and replaced with the new value. If it did not exist previously, it will be added to the current parameters. More...
NekDouble	GetParameter (std::string const &name)
	If a parameter with the specified name exists, it returns the NekDouble value that the parameter stores. If the parameter doesn't exist, it throws an exception. More...
NekDouble	GetTime () const
	Returns the total time spent in evaluation procedures, seconds. More...
int	DefineFunction (const std::string &vlist, const std::string &function)
	This function allows one to define a function to evaluate. The first argument (vlist) is a list of variables (separated by spaces) that the second argument (function) depends on. For example, if function = "x + y", then vlist should most likely be "x y", unless you are defining x or y as parameters with SetParameters. parsed expression ID. You will need this expression id to call evaluation methods below. More...
NekDouble	Evaluate (const int AnalyticExpression_id)
	Evaluation method for expressions depending on parameters only. More...
NekDouble	Evaluate (const int AnalyticExpression_id, const NekDouble, const NekDouble, const NekDouble, const NekDouble)
	Evaluation method for expressions depending on 4 variables (+parameters). More...
NekDouble	EvaluateAtPoint (const int AnalyticExpression_id, std::vector< NekDouble > point)
	Evaluation method for expressions depending on unspecified number of variables. This suitable for expressions depending on more than 4 variables or for the dynamic setting some variables as parameters (there is currently no interface method for removing a variable from parameter map though). More...
void	Evaluate (const int expression_id, const Array< OneD, const NekDouble > &, const Array< OneD, const NekDouble > &, const Array< OneD, const NekDouble > &, const Array< OneD, const NekDouble > &, Array< OneD, NekDouble > &result)
	Vectorized evaluation method for expressions depending on 4 variables. More...
void	Evaluate (const int expression_id, const std::vector< Array< OneD, const NekDouble > > points, Array< OneD, NekDouble > &result)
	Vectorized evaluation method for expressions depending on unspecified number of variables. More...

Private Types
enum	EvaluationStepType {   E_ABS, E_ASIN, E_ACOS, E_ATAN,   E_ATAN2, E_ANG, E_CEIL, E_COS,   E_COSH, E_EXP, E_FABS, E_FLOOR,   E_LOG, E_LOG10, E_POW, E_RAD,   E_SIN, E_SINH, E_SQRT, E_TAN,   E_TANH, E_SIGN, E_AWGN, E_BESSEL }
typedef std::vector< NekDouble > &	vr
	Short names to minimise the infractructural code mess in defining functors below. More...
typedef const std::vector < NekDouble > &	cvr
typedef const int	ci
typedef RandomGeneratorType &	rgt

Private Member Functions
PrecomputedValue	PrepareExecutionAsYouParse (const ParsedTreeIterator &root, ExecutionStack &stack, VariableMap &varMap, int stateIndex)
	This method prepares the execution stack (an ordered sequence of operators that perform the evaluation) for the parsed evaluation tree. More...
template<typename StepType >
EvaluationStep *	makeStep (ci dest, ci src_left=0, ci src_right=0)
	Factory method which makes code little less messy. More...

Private Attributes
boost_spirit::symbols< NekDouble >	m_constantsParser
ExpressionMap	m_parsedMapExprToExecStackId
	These vector and map store pre-processed evaluation sequences for the analytic expressions. Each ExecutionStack is an ordered container of steps of sequential execution process which evaluates an analytic expression. More...
std::vector< ExecutionStack >	m_executionStack
std::vector< VariableMap >	m_stackVariableMap
	Keeping map of variables individually per each analytic expression allows correctly handling expressions which depend on different number of variables. More...
ParameterMap	m_parameterMapNameToId
	The following data structures hold input data to be used on evaluation stage. There are three types of input data: More...
ConstantMap	m_constantMapNameToId
VariableMap	m_expressionVariableMap
std::vector< NekDouble >	m_parameter
std::vector< NekDouble >	m_constant
std::vector< NekDouble >	m_variable
std::vector< NekDouble >	m_state
	This vector stores the execution state (memory) used by the sequential execution process. More...
std::vector< int >	m_state_sizes
	Vector of state sizes per each. More...
int	m_state_size
	This counter is used by PrepareExecutionAsYouParse for finding the minimal state size necessary for evaluation of function parsed. More...
Timer	m_timer
	Timer and sum of evaluation times. More...
NekDouble	m_total_eval_time
RandomGeneratorType	m_generator
FunctionNameMap	m_functionMapNameToInstanceType
std::map< int, OneArgFunc >	m_function
std::map< int, TwoArgFunc >	m_function2

Detailed Description

This class defines evaluator of analytic (symbolic) mathematical expressions. Expressions are allowed to depend on a number of spatial-time variables and parameters. Pre-processing and evaluation stages are split. At evaluation stage one specifies values for each variable, resulting expression value is returned. Vectorized evaluator (evaluate expression at a set of points) is available.

Internally this class uses boost::spirit to parse analytic expressions and unrolls their recursive bracketing structure into a sequence of evaluation steps (aka execution stack) with resolved data dependencies. Once an expression is pre-processed, its execution stack is stored internally in order to be re-used.

Definition at line 114 of file AnalyticExpressionEvaluator.hpp.

Member Typedef Documentation

typedef const int Nektar::LibUtilities::AnalyticExpressionEvaluator::ci

private

Definition at line 469 of file AnalyticExpressionEvaluator.hpp.

typedef std::map<std::string, int> Nektar::LibUtilities::AnalyticExpressionEvaluator::ConstantMap

Definition at line 125 of file AnalyticExpressionEvaluator.hpp.

typedef const std::vector<NekDouble>& Nektar::LibUtilities::AnalyticExpressionEvaluator::cvr

private

Definition at line 468 of file AnalyticExpressionEvaluator.hpp.

typedef std::vector<EvaluationStep*> Nektar::LibUtilities::AnalyticExpressionEvaluator::ExecutionStack

Definition at line 129 of file AnalyticExpressionEvaluator.hpp.

typedef std::map<std::string, int> Nektar::LibUtilities::AnalyticExpressionEvaluator::ExpressionMap

Definition at line 127 of file AnalyticExpressionEvaluator.hpp.

typedef std::map<std::string, int> Nektar::LibUtilities::AnalyticExpressionEvaluator::FunctionNameMap

Definition at line 128 of file AnalyticExpressionEvaluator.hpp.

typedef NekDouble(* Nektar::LibUtilities::AnalyticExpressionEvaluator::OneArgFunc)(NekDouble)

Definition at line 131 of file AnalyticExpressionEvaluator.hpp.

typedef std::map<std::string, int> Nektar::LibUtilities::AnalyticExpressionEvaluator::ParameterMap

Definition at line 126 of file AnalyticExpressionEvaluator.hpp.

typedef boost_spirit::tree_parse_info< std::string::const_iterator, boost_spirit::node_val_data_factory<NekDouble> > Nektar::LibUtilities::AnalyticExpressionEvaluator::ParsedTreeInfo

Definition at line 137 of file AnalyticExpressionEvaluator.hpp.

typedef boost_spirit::tree_match< std::string::const_iterator, boost_spirit::node_val_data_factory<NekDouble> >::tree_iterator Nektar::LibUtilities::AnalyticExpressionEvaluator::ParsedTreeIterator

Definition at line 141 of file AnalyticExpressionEvaluator.hpp.

typedef std::pair<bool, NekDouble> Nektar::LibUtilities::AnalyticExpressionEvaluator::PrecomputedValue

Definition at line 130 of file AnalyticExpressionEvaluator.hpp.

typedef boost::mt19937 Nektar::LibUtilities::AnalyticExpressionEvaluator::RandomGeneratorType

Definition at line 145 of file AnalyticExpressionEvaluator.hpp.

typedef RandomGeneratorType& Nektar::LibUtilities::AnalyticExpressionEvaluator::rgt

private

Definition at line 470 of file AnalyticExpressionEvaluator.hpp.

typedef NekDouble(* Nektar::LibUtilities::AnalyticExpressionEvaluator::TwoArgFunc)(NekDouble, NekDouble)

Definition at line 132 of file AnalyticExpressionEvaluator.hpp.

typedef std::vector<const Array<OneD, const NekDouble>* > Nektar::LibUtilities::AnalyticExpressionEvaluator::VariableArray

Definition at line 143 of file AnalyticExpressionEvaluator.hpp.

typedef std::map<std::string, int> Nektar::LibUtilities::AnalyticExpressionEvaluator::VariableMap

Definition at line 119 of file AnalyticExpressionEvaluator.hpp.

typedef std::vector<NekDouble>& Nektar::LibUtilities::AnalyticExpressionEvaluator::vr

private

Short names to minimise the infractructural code mess in defining functors below.

Definition at line 467 of file AnalyticExpressionEvaluator.hpp.

Member Enumeration Documentation

enum Nektar::LibUtilities::AnalyticExpressionEvaluator::EvaluationStepType

private

Enumerator
E_ABS
E_ASIN
E_ACOS
E_ATAN
E_ATAN2
E_ANG
E_CEIL
E_COS
E_COSH
E_EXP
E_FABS
E_FLOOR
E_LOG
E_LOG10
E_POW
E_RAD
E_SIN
E_SINH
E_SQRT
E_TAN
E_TANH
E_SIGN
E_AWGN
E_BESSEL

Definition at line 479 of file AnalyticExpressionEvaluator.hpp.

            {
                    E_ABS,    E_ASIN,  E_ACOS,  E_ATAN,  E_ATAN2, E_ANG,
                    E_CEIL,   E_COS,   E_COSH,  E_EXP,   E_FABS,  E_FLOOR,
                    E_LOG,    E_LOG10, E_POW,   E_RAD,   E_SIN,   E_SINH,
                    E_SQRT,   E_TAN,   E_TANH,  E_SIGN,  E_AWGN, E_BESSEL
            };

Constructor & Destructor Documentation

Nektar::LibUtilities::AnalyticExpressionEvaluator::AnalyticExpressionEvaluator

(

void

)

Initializes the evaluator to a state where it is ready to accept input from the DefineFunction function.

Definition at line 220 of file AnalyticExpressionEvaluator.cpp.

References AddConstant(), Nektar::LibUtilities::ang(), E_ABS, E_ACOS, E_ANG, E_ASIN, E_ATAN, E_ATAN2, E_AWGN, E_BESSEL, E_CEIL, E_COS, E_COSH, E_EXP, E_FABS, E_FLOOR, E_LOG, E_LOG10, E_RAD, E_SIGN, E_SIN, E_SINH, E_SQRT, E_TAN, E_TANH, m_function, m_function2, m_functionMapNameToInstanceType, m_state_size, Nektar::LibUtilities::rad(), and Nektar::LibUtilities::sign().

                                                                :
                m_timer(),
                m_total_eval_time(0)
        {
            m_state_size = 1;

            AddConstant("MEANINGLESS", 0.0);
            AddConstant("E",           2.71828182845904523536);     // Natural logarithm
            AddConstant("LOG2E",       1.4426950408889634074);      // log_2 e
            AddConstant("LOG10E",      0.43429448190325182765);     // log_10 e
            AddConstant("LN2",         0.69314718055994530942);     // log_e 2
            AddConstant("LN10",        2.30258509299404568402);     // log_e 10
            AddConstant("PI",          3.14159265358979323846);     // pi
            AddConstant("PI_2",        1.57079632679489661923);     // pi/2
            AddConstant("PI_4",        0.78539816339744830962);     // pi/4
            AddConstant("1_PI",        0.31830988618379067154);     // 1/pi
            AddConstant("2_PI",        0.63661977236758134308);     // 2/pi
            AddConstant("2_SQRTPI",    1.12837916709551257390);     // 2/sqrt(pi)
            AddConstant("SQRT2",       1.41421356237309504880);     // sqrt(2)
            AddConstant("SQRT1_2",     0.70710678118654752440);     // 1/sqrt(2)
            AddConstant("GAMMA",       0.57721566490153286060);     // Euler
            AddConstant("DEG",         57.2957795130823208768);     // deg/radian
            AddConstant("PHI",         1.61803398874989484820);     // golden ratio

            m_functionMapNameToInstanceType["abs"]   =  E_ABS;
            m_functionMapNameToInstanceType["asin"]  =  E_ASIN;
            m_functionMapNameToInstanceType["acos"]  =  E_ACOS;
            m_functionMapNameToInstanceType["atan"]  =  E_ATAN;
            m_functionMapNameToInstanceType["atan2"] =  E_ATAN2;
            m_functionMapNameToInstanceType["ang"]   =  E_ANG;
            m_functionMapNameToInstanceType["bessel"]  =  E_BESSEL;
            m_functionMapNameToInstanceType["ceil"]  =  E_CEIL;
            m_functionMapNameToInstanceType["cos"]   =  E_COS;
            m_functionMapNameToInstanceType["cosh"]  =  E_COSH;
            m_functionMapNameToInstanceType["exp"]   =  E_EXP;
            m_functionMapNameToInstanceType["fabs"]  =  E_FABS;
            m_functionMapNameToInstanceType["floor"] =  E_FLOOR;
            m_functionMapNameToInstanceType["log"]   =  E_LOG;
            m_functionMapNameToInstanceType["log10"] =  E_LOG10;
            m_functionMapNameToInstanceType["rad"]   =  E_RAD;
            m_functionMapNameToInstanceType["sin"]   =  E_SIN;
            m_functionMapNameToInstanceType["sinh"]  =  E_SINH;
            m_functionMapNameToInstanceType["sqrt"]  =  E_SQRT;
            m_functionMapNameToInstanceType["tan"]   =  E_TAN;
            m_functionMapNameToInstanceType["tanh"]  =  E_TANH;
            m_functionMapNameToInstanceType["sign"]  =  E_SIGN;
            m_functionMapNameToInstanceType["awgn"]  =  E_AWGN;

            m_function[ E_ABS  ] = std::abs;
            m_function[ E_ASIN ] = asin;
            m_function[ E_ACOS ] = acos;
            m_function[ E_ATAN ] = atan;
            m_function[ E_CEIL ] = ceil;
            m_function[ E_COS  ] = cos;
            m_function[ E_COSH ] = cosh;
            m_function[ E_EXP  ] = exp;
            m_function[ E_FABS ] = fabs;
            m_function[ E_FLOOR] = floor;
            m_function[ E_LOG  ] = log;
            m_function[ E_LOG10] = log10;
            m_function[ E_SIN  ] = sin;
            m_function[ E_SINH ] = sinh;
            m_function[ E_SQRT ] = sqrt;
            m_function[ E_TAN  ] = tan;
            m_function[ E_TANH ] = tanh;
            m_function[ E_SIGN ] = sign;
            m_function2[E_ATAN2] = atan2;
            m_function2[E_ANG]   = ang;
            m_function2[E_RAD]   = rad;
            m_function2[E_BESSEL]   = boost::math::cyl_bessel_j;

            // there is no entry to m_function that correspond to awgn function.
            // this is made in purpose. This function need not be pre-evaluated once!
        }

Nektar::LibUtilities::AnalyticExpressionEvaluator::~AnalyticExpressionEvaluator

(

void

)

Destroys the execution stack.

Definition at line 296 of file AnalyticExpressionEvaluator.cpp.

References Nektar::iterator, and m_executionStack.

        {
            for (std::vector<ExecutionStack>::iterator it_es = m_executionStack.begin(); it_es != m_executionStack.end(); ++it_es)
            {
                for (std::vector<EvaluationStep*>::iterator it = (*it_es).begin(); it != (*it_es).end(); ++it)
                {
                    delete *it;
                }
                (*it_es).clear();
            }
            m_executionStack.clear();
        }

Member Function Documentation

int Nektar::LibUtilities::AnalyticExpressionEvaluator::AddConstant	(	std::string const &	name,
		NekDouble	value
	)

This function behaves in the same way as AddConstants, but it only adds one constant at a time. If the constant existed previously, an exception will be thrown stating the fact. If it did not exist previously, it will be added to the global constants and will be used the next time DefineFunction is called.

Definition at line 324 of file AnalyticExpressionEvaluator.cpp.

References m_constant, m_constantMapNameToId, and m_constantsParser.

Referenced by AddConstants(), AnalyticExpressionEvaluator(), DefineFunction(), and PrepareExecutionAsYouParse().

        {
            ConstantMap::const_iterator it = m_constantMapNameToId.find(name);
            if (it == m_constantMapNameToId.end())
            {
                // we are trying to avoid duplicating entries in m_constantParser and m_constants
                m_constantsParser.add(name.c_str(), value);
                int index = m_constant.size();
                m_constantMapNameToId[name] = index;
                m_constant.push_back(value);
                return index;
            }
            else
            {
          if(m_constant[it->second] != value)
          {
            std::string errormsg("Attempt to add numerically different constants under the same name: ");
            errormsg += name;
            std::cout << errormsg << std::endl;
          }
        //ASSERTL1(m_constant[it->second] == value, "Attempt to add numerically different constants under the same name: " + name);
            }
            return it->second;
        }

void Nektar::LibUtilities::AnalyticExpressionEvaluator::AddConstants

(

std::map< std::string, NekDouble > const &

constants

)

Constants are evaluated and inserted into the function at the time it is parsed when calling the DefineFunction function. After parsing, if a constant is changed, it will not be reflected in the function when Evaluate is called. This also means that if a function with an unknown constant is added, and then the constant is added, the function will not see the added constant and through an exception. This function will add all of the constants in the map argument to the global internal constants. If a constant was already loaded previously, it will throw an exception stating which constants in the map had this issue. It will add all of the constants it can and output the constants it couldn't add in the string exception.

Definition at line 316 of file AnalyticExpressionEvaluator.cpp.

References AddConstant().

Referenced by Nektar::LibUtilities::Equation::SetConstants().

        {
            for (std::map<std::string, NekDouble>::const_iterator it = constants.begin(); it != constants.end(); ++it)
            {
                AddConstant(it->first, it->second);
            }
        }

int Nektar::LibUtilities::AnalyticExpressionEvaluator::DefineFunction	(	const std::string &	vlist,
		const std::string &	function
	)

This function allows one to define a function to evaluate. The first argument (vlist) is a list of variables (separated by spaces) that the second argument (function) depends on. For example, if function = "x + y", then vlist should most likely be "x y", unless you are defining x or y as parameters with SetParameters. parsed expression ID. You will need this expression id to call evaluation methods below.

Definition at line 402 of file AnalyticExpressionEvaluator.cpp.

References AddConstant(), ASSERTL1, m_constantsParser, m_executionStack, m_parsedMapExprToExecStackId, m_stackVariableMap, m_state_size, m_state_sizes, and PrepareExecutionAsYouParse().

Referenced by Nektar::NekMeshUtils::CurveMesh::CurveMesh(), Nektar::LibUtilities::Equation::Equation(), Nektar::NekMeshUtils::Generator2D::Process(), Nektar::Utilities::ProcessScalar::Process(), Nektar::SpatialDomains::MeshGraph::ReadCurves(), Nektar::SpatialDomains::MeshGraph::ReadGeometry(), and Nektar::Utilities::ProcessCurve::v_GenerateEdgeNodes().

        {
            // Find the previous parsing.
            ExpressionMap::const_iterator it = m_parsedMapExprToExecStackId.find(expr);
            if (it != m_parsedMapExprToExecStackId.end())
            {
                // if this function is already defined, don't do anything but
                // return its ID.
                return it->second;
            }

            // ----------------------------------------------
            // Prepare an iterator that allows to walk along
            // the string representing an analytic expression in the order
            // that respects its recursive structure (thanks to boost::spirit).
            // ----------------------------------------------

            // Parse the vlist input and separate the variables into ordered entries
            // in a vector<string> object. These need to be ordered because this is
            // the order the variables will get assigned to in the Map when Evaluate(...)
            // is called.
            std::vector<std::string> variableNames;
            parse((char*) vlist.c_str(), ( *space_p >>
                       *(
                                +(+graph_p)[push_back_a(variableNames)]
                                    >> +space_p
                             )
                        )
            );
            // Set up our grammar
            AnalyticExpression myGrammar(&m_constantsParser, variableNames);

            // Do the actual parsing with boost::spirit and alert the user if there was an error with an exception.
            ParsedTreeInfo   parseInfo = ast_parse<
                                                node_val_data_factory<NekDouble>,
                                                std::string::const_iterator,
                                                AnalyticExpression,
                                                space_parser
                                             >
                                             (expr.begin(), expr.end(), myGrammar, space_p);

            ASSERTL1(parseInfo.full != false, "Unable to fully parse function. Stopped just before: "
                                         + std::string(parseInfo.stop, parseInfo.stop + 15));
            if (!parseInfo.full)
            {
                throw std::runtime_error("Unable to fully parse function at: "
                                        + std::string(parseInfo.stop, parseInfo.stop + 15));
            }


            // ----------------------------------------------
            // Data parsed, start setting up internal data structures.
            // ----------------------------------------------

            ExecutionStack  stack;
            VariableMap     variableMap;

            int stackId = m_executionStack.size();
            m_state_size = 1;

            // register all variables declared in the expression
            for (int i = 0; i < variableNames.size(); i++)
            {
                variableMap[variableNames[i]] = i;
            }

            // then prepare an execution stack.
            // this method also calculates a length of internal
            // state storage (m_state_size) for this function.
            PrecomputedValue v = PrepareExecutionAsYouParse(parseInfo.trees.begin(), stack, variableMap, 0);

            // constant expression, fully evaluated
            if (true == v.first)
            {
                ASSERTL1(stack.size() == 0, "Constant expression yeilds non-empty execution stack. Bug in PrepareExecutionAsYouParse()");

                int const_index = AddConstant(std::string("EXPRESSION_") + boost::lexical_cast<std::string>(stackId), v.second);
                stack.push_back ( makeStep<StoreConst>( 0, const_index ) );
            }

            m_parsedMapExprToExecStackId[expr] = stackId;

            // the execution stack and its corresponding variable index map are
            // two parallel std::vectors that share their ids. This split helps
            // to achieve some performance improvement.
            m_executionStack.push_back(stack);
            m_stackVariableMap.push_back(variableMap);
            m_state_sizes.push_back(m_state_size);
            return stackId;
        }

NekDouble Nektar::LibUtilities::AnalyticExpressionEvaluator::Evaluate

(

const int

AnalyticExpression_id

)

Evaluation method for expressions depending on parameters only.

Definition at line 494 of file AnalyticExpressionEvaluator.cpp.

References ASSERTL1, m_executionStack, m_state, m_state_sizes, m_timer, m_total_eval_time, Nektar::Timer::Start(), Nektar::Timer::Stop(), and Nektar::Timer::TimePerTest().

Referenced by Nektar::LibUtilities::Equation::Evaluate(), Evaluate(), Nektar::Utilities::ProcessCurve::EvaluateCoordinate(), Nektar::NekMeshUtils::Generator2D::MakeBL(), Nektar::SpatialDomains::MeshGraph::ReadCurves(), and Nektar::SpatialDomains::MeshGraph::ReadGeometry().

        {
            m_timer.Start();

            ASSERTL1(m_executionStack.size() > expression_id, "unknown analytic expression, it must first be defined with DefineFunction(...)");

            ExecutionStack &stack = m_executionStack[expression_id];

            m_state.resize(m_state_sizes[expression_id]);
            for (int i = 0; i < stack.size(); i++)
            {
                (*stack[i]).run_once();
            }

            m_timer.Stop();
            m_total_eval_time += m_timer.TimePerTest(1);

            return m_state[0];
        }

NekDouble Nektar::LibUtilities::AnalyticExpressionEvaluator::Evaluate	(	const int	AnalyticExpression_id,
		const NekDouble	x,
		const NekDouble	y,
		const NekDouble	z,
		const NekDouble	t
	)

Evaluation method for expressions depending on 4 variables (+parameters).

Definition at line 514 of file AnalyticExpressionEvaluator.cpp.

References ASSERTL1, m_executionStack, m_state, m_state_sizes, m_timer, m_total_eval_time, m_variable, Nektar::Timer::Start(), Nektar::Timer::Stop(), and Nektar::Timer::TimePerTest().

        {
            m_timer.Start();

            ASSERTL1(m_executionStack.size() > expression_id, "unknown analytic expression, it must first be defined with DefineFunction(...)");

            ExecutionStack &stack = m_executionStack[expression_id];

            // initialise internal vector of variable values
            m_state.resize(m_state_sizes[expression_id]);

            if (m_variable.size() < 4)
            {
                m_variable.resize(4);
            }

            // no flexibility, no change of variable ordering in m_variable
            // container depending on their names ordering in the input vlist
            // argument of DefineFunction. Ordering convention (x,y,z,t) is assumed.
            m_variable[0] = x;
            m_variable[1] = y;
            m_variable[2] = z;
            m_variable[3] = t;

            // main execution cycle is hidden here
            for (int i = 0; i < stack.size(); i++)
            {
                (*stack[i]).run_once();
            }

            m_timer.Stop();
            m_total_eval_time += m_timer.TimePerTest(1);

            return m_state[0];
        }

void Nektar::LibUtilities::AnalyticExpressionEvaluator::Evaluate	(	const int	expression_id,
		const Array< OneD, const NekDouble > &	x,
		const Array< OneD, const NekDouble > &	y,
		const Array< OneD, const NekDouble > &	z,
		const Array< OneD, const NekDouble > &	t,
		Array< OneD, NekDouble > &	result
	)

Vectorized evaluation method for expressions depending on 4 variables.

Definition at line 588 of file AnalyticExpressionEvaluator.cpp.

References Evaluate(), m_timer, m_total_eval_time, Nektar::Timer::Start(), Nektar::Timer::Stop(), and Nektar::Timer::TimePerTest().

        {
            m_timer.Start();

            std::vector<Array<OneD, const NekDouble> >points;

            points.push_back(x);
            points.push_back(y);
            points.push_back(z);
            points.push_back(t);
            
            Evaluate(expression_id,points,result);

            m_timer.Stop();
            m_total_eval_time += m_timer.TimePerTest(1);
        }

void Nektar::LibUtilities::AnalyticExpressionEvaluator::Evaluate	(	const int	expression_id,
		const std::vector< Array< OneD, const NekDouble > >	points,
		Array< OneD, NekDouble > &	result
	)

Vectorized evaluation method for expressions depending on unspecified number of variables.

If number of points tends to 10^6, one may end up with up to ~0.5Gb data allocated for m_state only. Lets split the work into cache-sized chunks. Ahtung, magic constant!

Definition at line 612 of file AnalyticExpressionEvaluator.cpp.

References ASSERTL1, m_executionStack, m_state, m_state_sizes, m_timer, m_total_eval_time, m_variable, Nektar::Timer::Start(), Nektar::Timer::Stop(), and Nektar::Timer::TimePerTest().

        {
            m_timer.Start();

            const int num_points = points[0].num_elements();
            ASSERTL1(m_executionStack.size() > expression_id,
                     "unknown analytic expression, it must first be defined "
                     "with DefineFunction(...)");
            ASSERTL1(result.num_elements() >= num_points,
                     "destination array must have enough capacity to store "
                     "expression values at each given point");

            ExecutionStack &stack = m_executionStack[expression_id];

            /// If number of points tends to 10^6, one may end up
            /// with up to ~0.5Gb data allocated for m_state only.
            /// Lets split the work into cache-sized chunks.
            /// Ahtung, magic constant!
            const int max_chunk_size = 1024;
            const int nvals = points.size();
            const int chunk_size = (std::min)(max_chunk_size, num_points);

            if (m_state.size() < chunk_size * m_state_sizes[expression_id])
            {
                m_state.resize(m_state_sizes[expression_id] * chunk_size, 0.0);
            }
            if (m_variable.size() < nvals * chunk_size)
            {
                m_variable.resize( nvals * chunk_size, 0.0);
            }
            if (result.num_elements() < num_points)
            {
                result = Array<OneD, NekDouble>(num_points, 0.0);
            }

            int offset = 0;
            int work_left = num_points;
            while(work_left > 0)
            {
                const int this_chunk_size = (std::min)(work_left, 1024);
                for (int i = 0; i < this_chunk_size; i++)
                {
                    for(int j = 0; j < nvals; ++j)
                    {
                        m_variable[i+this_chunk_size*j] = points[j][offset + i];
                    }
                }
                for (int i = 0; i < stack.size(); i++)
                {
                    (*stack[i]).run_many(this_chunk_size);
                }
                for (int i = 0; i < this_chunk_size; i++)
                {
                    result[offset + i] = m_state[i];
                }
                work_left -= this_chunk_size;
                offset    += this_chunk_size;
            }
            m_timer.Stop();
            m_total_eval_time += m_timer.TimePerTest(1);
        }

NekDouble Nektar::LibUtilities::AnalyticExpressionEvaluator::EvaluateAtPoint	(	const int	AnalyticExpression_id,
		std::vector< NekDouble >	point
	)

Evaluation method for expressions depending on unspecified number of variables. This suitable for expressions depending on more than 4 variables or for the dynamic setting some variables as parameters (there is currently no interface method for removing a variable from parameter map though).

Definition at line 555 of file AnalyticExpressionEvaluator.cpp.

References ASSERTL1, m_executionStack, m_stackVariableMap, m_state, m_state_sizes, m_timer, m_total_eval_time, m_variable, Nektar::Timer::Start(), Nektar::Timer::Stop(), and Nektar::Timer::TimePerTest().

        {
            m_timer.Start();

            ASSERTL1(m_executionStack.size() > expression_id, "unknown analytic expression, it must first be defined with DefineFunction(...)");

            ExecutionStack&  stack    = m_executionStack[expression_id];
            VariableMap&  variableMap = m_stackVariableMap[expression_id];

            ASSERTL1(point.size() == variableMap.size(), "The number of variables used to define this expression should match the point dimensionality.");

            // initialise internal vector of variable values
            m_state.resize(m_state_sizes[expression_id]);
            m_variable.resize(point.size());
            VariableMap::const_iterator it;
            for (it = variableMap.begin(); it != variableMap.end(); ++it)
            {
                m_variable[it->second] = point[it->second];
            }
            // main execution cycle is hidden here
            for (int i = 0; i < stack.size(); i++)
            {
                (*stack[i]).run_once();
            }

            m_timer.Stop();
            m_total_eval_time += m_timer.TimePerTest(1);

            return m_state[0];
        }

NekDouble Nektar::LibUtilities::AnalyticExpressionEvaluator::GetConstant

(

std::string const &

name

)

If a constant with the specified name exists, it returns the NekDouble value that the constant stores. If the constant doesn't exist, it throws an exception.

Definition at line 349 of file AnalyticExpressionEvaluator.cpp.

References ASSERTL1, Nektar::StdRegions::find(), and m_constantsParser.

        {
            NekDouble* value = find(m_constantsParser, name.c_str());

            ASSERTL1(value != NULL, "Constant variable not found: " + name);

            return *value;
        }

NekDouble Nektar::LibUtilities::AnalyticExpressionEvaluator::GetParameter

(

std::string const &

name

)

If a parameter with the specified name exists, it returns the NekDouble value that the parameter stores. If the parameter doesn't exist, it throws an exception.

Definition at line 382 of file AnalyticExpressionEvaluator.cpp.

References ASSERTL1, m_parameter, and m_parameterMapNameToId.

        {
            ParameterMap::const_iterator it = m_parameterMapNameToId.find(name);

            ASSERTL1(it != m_parameterMapNameToId.end(), "Parameter not found: " + name);

            return m_parameter[ it->second ];
        }

NekDouble Nektar::LibUtilities::AnalyticExpressionEvaluator::GetTime

(

)

const

Returns the total time spent in evaluation procedures, seconds.

Definition at line 392 of file AnalyticExpressionEvaluator.cpp.

References m_total_eval_time.

Referenced by Nektar::LibUtilities::Equation::GetTime().

        {
            return m_total_eval_time;
        }

template<typename StepType >

EvaluationStep* Nektar::LibUtilities::AnalyticExpressionEvaluator::makeStep ( ci  dest, ci  src_left = 0, ci  src_right = 0  )

inlineprivate

Factory method which makes code little less messy.

Definition at line 474 of file AnalyticExpressionEvaluator.hpp.

            {
                return ( new StepType ( m_generator,m_state,m_constant,m_parameter,m_variable,dest,src_left,src_right ) );
            }

AnalyticExpressionEvaluator::PrecomputedValue Nektar::LibUtilities::AnalyticExpressionEvaluator::PrepareExecutionAsYouParse ( const ParsedTreeIterator &  root, ExecutionStack &  stack, VariableMap &  varMap, int  stateIndex  )

private

This method prepares the execution stack (an ordered sequence of operators that perform the evaluation) for the parsed evaluation tree.

In order to do this, it unrolls binary tree representing the recursive evaluation into an ordered sequence of commands. That ordered sequence of commands is equivalent to bottom-up walk up the evaluation tree, but this allows not to form tree explicitly.

This approach requires to introduce explicitly an execution state (memory) shared by commands in the evaluation sequence: recursively dependent commands need to pass data between each other. Such state for the recursive evaluation is passed via return values of a recursive evaluation function — which is bad if one wants to implement vectorized evaluator.

On the other hand, to run through a sequential container of functors is faster than to walk the tree and at each node to check the node type.

root - iterator generated by boost::spirit; stack - initially empty sequential container of evaluation steps; varMap - maps variable names to their ids; stateIndex - an index in state[] array where an evaluation step corresponding to the current tree node is allowed to write. an std::pair<bool, NekDouble> which encodes fully pre-evaluated NekDouble value as pair <true, value> if all sub-tree down the current node evaluates to constant, or flags the opposite via pair <false,0>.

Definition at line 678 of file AnalyticExpressionEvaluator.cpp.

References AddConstant(), ASSERTL0, ASSERTL1, Nektar::LibUtilities::AnalyticExpressionEvaluator::AnalyticExpression::constantID, E_ABS, E_ACOS, E_ANG, E_ASIN, E_ATAN, E_ATAN2, E_AWGN, E_BESSEL, E_CEIL, E_COS, E_COSH, E_EXP, E_FABS, E_FLOOR, E_LOG, E_LOG10, E_RAD, E_SIGN, E_SIN, E_SINH, E_SQRT, E_TAN, E_TANH, Nektar::LibUtilities::AnalyticExpressionEvaluator::AnalyticExpression::factorID, Nektar::LibUtilities::AnalyticExpressionEvaluator::AnalyticExpression::functionID, m_constant, m_constantMapNameToId, m_function, m_function2, m_functionMapNameToInstanceType, m_parameterMapNameToId, m_state_size, Nektar::LibUtilities::AnalyticExpressionEvaluator::AnalyticExpression::numberID, Nektar::LibUtilities::AnalyticExpressionEvaluator::AnalyticExpression::operatorID, Nektar::LibUtilities::AnalyticExpressionEvaluator::AnalyticExpression::parameterID, and Nektar::LibUtilities::AnalyticExpressionEvaluator::AnalyticExpression::variableID.

Referenced by DefineFunction().

        {
            std::string valueStr(location->value.begin(), location->value.end());
            boost::algorithm::trim(valueStr);

            const parser_id parserID  = location->value.id();
#if defined(NEKTAR_DEBUG) || defined(NEKTAR_FULLDEBUG)
            const int num_children    = location->children.size();
#endif

            if (parserID == AnalyticExpression::constantID)
            {
                ASSERTL1(num_children == 0, "Illegal children under constant node: " + valueStr);

                ConstantMap::const_iterator it = m_constantMapNameToId.find(valueStr);
                ASSERTL1(it != m_constantMapNameToId.end(), "Cannot find the value for the specified constant: " + valueStr);

                return std::make_pair(true, m_constant[it->second]);
            }
            else if (parserID == AnalyticExpression::numberID)
            {
                ASSERTL1(num_children == 0, "Illegal children under number node: " + valueStr);
                return std::make_pair(true, boost::lexical_cast<NekDouble>(valueStr.c_str()) );
            }
            else if (parserID == AnalyticExpression::variableID)
            {
                ASSERTL1(num_children == 0, "Illegal children under variable node: " + valueStr);

                VariableMap::const_iterator it = variableMap.find(valueStr);
                ASSERTL1(it != variableMap.end(), "Unknown variable parsed: " + valueStr);

                // Variables are not defined at the time of this parse.
                stack.push_back ( makeStep<StoreVar>( stateIndex, it->second ) );
                return std::make_pair(false, 0);
            }
            else if (parserID == AnalyticExpression::parameterID)
            {
                ASSERTL1(num_children == 0, "Illegal children under parameter node: " + valueStr);

                ParameterMap::const_iterator it = m_parameterMapNameToId.find(valueStr);
                ASSERTL1(it != m_parameterMapNameToId.end(), "Unknown parameter parsed: " + valueStr);

                // Parameters may change in between of evalutions.
                stack.push_back ( makeStep<StorePrm>( stateIndex, it->second ) );
                return std::make_pair(false, 0);
            }
            else if (parserID == AnalyticExpression::functionID)
            {
                FunctionNameMap::const_iterator it = m_functionMapNameToInstanceType.find(valueStr);
                ASSERTL1(it != m_functionMapNameToInstanceType.end(), "Invalid function specified: " + valueStr);
                ASSERTL1(num_children == 1 || num_children == 2, "Function " + valueStr + " would like to have too few or too many arguments. This is not implemented yet");

                if (location->children.size() == 1)
                {
                    PrecomputedValue v = PrepareExecutionAsYouParse(location->children.begin(), stack, variableMap, stateIndex);

                    // additive white gaussian noise function
                    if (it->second == E_AWGN)
                    {
                        int const_index = AddConstant(std::string("SUB_EXPR_") + boost::lexical_cast<std::string>(m_constant.size()), v.second);
                        stack.push_back ( makeStep<StoreConst>( stateIndex, const_index ) );
                        stack.push_back ( makeStep<EvalAWGN>( stateIndex, stateIndex ) );
                        return std::make_pair(false,0);
                    }

                    if (true == v.first)
                    {
                        return std::make_pair( true, m_function[it->second](v.second) );
                    }
                }
                else
                {
                    PrecomputedValue v1 = PrepareExecutionAsYouParse(location->children.begin()+0, stack, variableMap, stateIndex);
                    PrecomputedValue v2 = PrepareExecutionAsYouParse(location->children.begin()+1, stack, variableMap, stateIndex+1);
                    m_state_size++;

                    if (true == v1.first && true == v2.first)
                    {
                        return std::make_pair( true, m_function2[it->second](v1.second, v2.second) );
                    }
                }

                // if somewhere down the parse tree there is a variable or parameter, set up an
                // evaluation sequence.
                switch (it->second)
                {
                    case E_ABS:
                        stack.push_back ( makeStep<EvalAbs>( stateIndex, stateIndex) );
                        return std::make_pair(false,0);
                    case E_ASIN:
                        stack.push_back ( makeStep<EvalAsin>( stateIndex, stateIndex) );
                        return std::make_pair(false,0);
                    case E_ACOS:
                        stack.push_back ( makeStep<EvalAcos>( stateIndex, stateIndex ) );
                        return std::make_pair(false,0);
                    case E_ATAN:
                        stack.push_back ( makeStep<EvalAtan>( stateIndex, stateIndex ) );
                        return std::make_pair(false,0);
                    case E_ATAN2:
                        stack.push_back ( makeStep<EvalAtan2>( stateIndex, stateIndex, stateIndex+1 ) );
                        return std::make_pair(false,0);
                    case E_ANG:
                        stack.push_back ( makeStep<EvalAng>( stateIndex, stateIndex, stateIndex+1 ) );
                        return std::make_pair(false,0);
                    case E_BESSEL:
                        stack.push_back ( makeStep<EvalBessel>( stateIndex, stateIndex, stateIndex+1 ) );
                        return std::make_pair(false,0);
                    case E_CEIL:
                        stack.push_back ( makeStep<EvalCeil>( stateIndex, stateIndex ) );
                        return std::make_pair(false,0);
                    case E_COS:
                        stack.push_back ( makeStep<EvalCos>( stateIndex, stateIndex ) );
                        return std::make_pair(false,0);
                    case E_COSH:
                        stack.push_back ( makeStep<EvalCosh>( stateIndex, stateIndex ) );
                        return std::make_pair(false,0);
                    case E_EXP:
                        stack.push_back ( makeStep<EvalExp>( stateIndex, stateIndex ) );
                        return std::make_pair(false,0);
                    case E_FABS:
                        stack.push_back ( makeStep<EvalFabs>( stateIndex, stateIndex ) );
                        return std::make_pair(false,0);
                    case E_FLOOR:
                        stack.push_back ( makeStep<EvalFloor>( stateIndex, stateIndex ) );
                        return std::make_pair(false,0);
                    case E_LOG:
                        stack.push_back ( makeStep<EvalLog>( stateIndex, stateIndex ) );
                        return std::make_pair(false,0);
                    case E_LOG10:
                        stack.push_back ( makeStep<EvalLog10>( stateIndex, stateIndex ) );
                        return std::make_pair(false,0);
                    case E_RAD:
                        stack.push_back ( makeStep<EvalRad>( stateIndex, stateIndex, stateIndex+1 ) );
                        return std::make_pair(false,0);
                    case E_SIN:
                        stack.push_back ( makeStep<EvalSin>( stateIndex, stateIndex ) );
                        return std::make_pair(false,0);
                    case E_SINH:
                        stack.push_back ( makeStep<EvalSinh>( stateIndex, stateIndex ) );
                        return std::make_pair(false,0);
                    case E_SQRT:
                        stack.push_back ( makeStep<EvalSqrt>( stateIndex, stateIndex ) );
                        return std::make_pair(false,0);
                    case E_TAN:
                        stack.push_back ( makeStep<EvalTan>( stateIndex, stateIndex ) );
                        return std::make_pair(false,0);
                    case E_TANH:
                        stack.push_back ( makeStep<EvalTanh>( stateIndex, stateIndex ) );
                        return std::make_pair(false,0);
                    case E_SIGN:
                        stack.push_back ( makeStep<EvalSign>( stateIndex, stateIndex ) );
                        return std::make_pair(false,0);
                    default:
                        ASSERTL0(false, "Evaluation of " + valueStr + " is not implemented yet");
                }
                return std::make_pair(false,0);
            }
            else if (parserID == AnalyticExpression::factorID)
            {
                ASSERTL1(*valueStr.begin() == '-', "Illegal factor - it can only be '-' and it was: " + valueStr);
                ASSERTL1(num_children == 1, "Illegal number of children under factor node: " + valueStr);

                PrecomputedValue v = PrepareExecutionAsYouParse(location->children.begin(), stack, variableMap, stateIndex);

                // if precomputed value is valid, process it further.
                if (true == v.first)
                {
                    return std::make_pair( true, - v.second );
                }
                stack.push_back (makeStep<EvalNeg>( stateIndex, stateIndex) );
                return std::make_pair(false,0);
            }
            else if (parserID == AnalyticExpression::operatorID)
            {
                ASSERTL1(num_children == 2, "Too few or too many arguments for mathematical operator: " + valueStr);
                PrecomputedValue left  = PrepareExecutionAsYouParse(location->children.begin()+0, stack, variableMap, stateIndex);
                PrecomputedValue right = PrepareExecutionAsYouParse(location->children.begin()+1, stack, variableMap, stateIndex+1);
                m_state_size++;

                // if both precomputed values are valid, process them further.
                if ((true == left.first) && (true == right.first))
                {
                    switch(*valueStr.begin())
                    {
                    case '+':
                        return std::make_pair( true, left.second + right.second );
                    case '-':
                        return std::make_pair( true, left.second - right.second );
                    case '*':
                        return std::make_pair( true, left.second * right.second );
                    case '/':
                        return std::make_pair( true, left.second / right.second );
                    case '^':
                        return std::make_pair( true, std::pow(left.second, right.second) );
                    case '=':
                        return std::make_pair( true, left.second == right.second );
                    case '<':
                        if (*(valueStr.end()-1) == '=')
                        {
                            return std::make_pair( true, left.second <= right.second );
                        }
                        else
                        {
                            return std::make_pair( true, left.second < right.second );
                        }
                        return std::make_pair(false,0);
                    case '>':
                        if (*(valueStr.end()-1) == '=')
                        {
                            return std::make_pair( true, left.second >= right.second );
                        }
                        else
                        {
                            return std::make_pair( true, left.second > right.second );
                        }
                        return std::make_pair(false,0);
                    default:
                        ASSERTL0(false, "Invalid operator encountered: " + valueStr);
                    }
                    return std::make_pair(false,0);
                }

                // either operator argument is not fully evaluated
                // add pre-evaluated value to the contaner of constants
                if (true == left.first)
                {
                    int const_index = AddConstant(std::string("SUB_EXPR_") + boost::lexical_cast<std::string>(m_constant.size()), left.second);
                    stack.push_back ( makeStep<StoreConst>( stateIndex, const_index ) );
                }
                if (true == right.first)
                {
                    int const_index = AddConstant(std::string("SUB_EXPR_") + boost::lexical_cast<std::string>(m_constant.size()), right.second);
                    stack.push_back ( makeStep<StoreConst>( stateIndex+1, const_index ) );
                }


                switch(*valueStr.begin())
                {
                case '+':
                    stack.push_back (makeStep<EvalSum>( stateIndex, stateIndex, stateIndex+1 ) );
                    return std::make_pair(false,0);
                case '-':
                    stack.push_back (makeStep<EvalSub> (stateIndex, stateIndex, stateIndex+1 ) );
                    return std::make_pair(false,0);
                case '*':
                    stack.push_back (makeStep<EvalMul>( stateIndex, stateIndex, stateIndex+1 ) );
                    return std::make_pair(false,0);
                case '/':
                    stack.push_back (makeStep<EvalDiv>( stateIndex, stateIndex, stateIndex+1 ) );
                    return std::make_pair(false,0);
                case '^':
                    stack.push_back (makeStep<EvalPow>( stateIndex, stateIndex, stateIndex+1 ) );
                    return std::make_pair(false,0);
                case '=':
                    stack.push_back (makeStep<EvalLogicalEqual>( stateIndex, stateIndex, stateIndex+1 ) );
                    return std::make_pair(false,0);
                case '<':
                    if (*(valueStr.end()-1) == '=')
                    {
                        stack.push_back (makeStep<EvalLogicalLeq>( stateIndex, stateIndex, stateIndex+1 ) );
                    }
                    else
                    {
                        stack.push_back (makeStep<EvalLogicalLess>( stateIndex, stateIndex, stateIndex+1 ) );
                    }
                    return std::make_pair(false,0);

                case '>':
                    if (*(valueStr.end()-1) == '=')
                    {
                        stack.push_back (makeStep<EvalLogicalGeq>( stateIndex, stateIndex, stateIndex+1 ) );
                    }
                    else
                    {
                        stack.push_back (makeStep<EvalLogicalGreater>( stateIndex, stateIndex, stateIndex+1 ) );
                    }
                    return std::make_pair(false,0);

                default:
                    ASSERTL0(false, "Invalid operator encountered: " + valueStr);
                }
                return std::make_pair(false,0);
            }
            ASSERTL0(false, "Illegal expression encountered: " + valueStr);
            return std::make_pair(false,0);
        }

void Nektar::LibUtilities::AnalyticExpressionEvaluator::SetParameter	(	std::string const &	name,
		NekDouble	value
	)

This function behaves in the same way as SetParameters, but it only adds one parameter and it does not delete the others. If the parameter existed previously, it will be overridden and replaced with the new value. If it did not exist previously, it will be added to the current parameters.

Definition at line 366 of file AnalyticExpressionEvaluator.cpp.

References m_parameter, and m_parameterMapNameToId.

Referenced by Nektar::LibUtilities::Equation::SetParameter(), and SetParameters().

        {
            ParameterMap::const_iterator it = m_parameterMapNameToId.find(name);
            if (it == m_parameterMapNameToId.end())
            {
                m_parameterMapNameToId[name] = m_parameter.size();
                m_parameter.push_back(value);
            }
            else
            {
                // if parameter is known, change its value
                m_parameter[ it->second ] = value;
            }
        }

void Nektar::LibUtilities::AnalyticExpressionEvaluator::SetParameters

(

std::map< std::string, NekDouble > const &

params

)

Parameters are like constants, but they are inserted into the function at the time Evaluate is called instead of when the function is parsed. This function can be called at any time, and it will take effect in the next call to Evaluate. This function will delete all of the parameters, and replace all of them with only the ones in the map argument.

Definition at line 358 of file AnalyticExpressionEvaluator.cpp.

References SetParameter().

        {
            for (std::map<std::string, NekDouble>::const_iterator it = params.begin(); it != params.end(); it++)
            {
                SetParameter(it->first, it->second);
            }
        }

void Nektar::LibUtilities::AnalyticExpressionEvaluator::SetRandomSeed

(

unsigned int

seed = 123u

)

Definition at line 310 of file AnalyticExpressionEvaluator.cpp.

References m_generator.

        {
            m_generator.seed(seed);
        }

Member Data Documentation

std::vector<NekDouble> Nektar::LibUtilities::AnalyticExpressionEvaluator::m_constant

private

Definition at line 426 of file AnalyticExpressionEvaluator.hpp.

Referenced by AddConstant(), and PrepareExecutionAsYouParse().

ConstantMap Nektar::LibUtilities::AnalyticExpressionEvaluator::m_constantMapNameToId

private

Definition at line 422 of file AnalyticExpressionEvaluator.hpp.

Referenced by AddConstant(), and PrepareExecutionAsYouParse().

boost_spirit::symbols<NekDouble> Nektar::LibUtilities::AnalyticExpressionEvaluator::m_constantsParser

private

This is a parser for spirit that parses the CONSTANT values. The default constants are those that are in math.h without the M_ prefix and they are initialized in the AnalyticExpressionEvaluator constructor.

Definition at line 313 of file AnalyticExpressionEvaluator.hpp.

Referenced by AddConstant(), DefineFunction(), and GetConstant().

std::vector<ExecutionStack> Nektar::LibUtilities::AnalyticExpressionEvaluator::m_executionStack

private

Definition at line 396 of file AnalyticExpressionEvaluator.hpp.

Referenced by DefineFunction(), Evaluate(), EvaluateAtPoint(), and ~AnalyticExpressionEvaluator().

VariableMap Nektar::LibUtilities::AnalyticExpressionEvaluator::m_expressionVariableMap

private

Definition at line 423 of file AnalyticExpressionEvaluator.hpp.

std::map<int, OneArgFunc> Nektar::LibUtilities::AnalyticExpressionEvaluator::m_function

private

Definition at line 459 of file AnalyticExpressionEvaluator.hpp.

Referenced by AnalyticExpressionEvaluator(), and PrepareExecutionAsYouParse().

std::map<int, TwoArgFunc> Nektar::LibUtilities::AnalyticExpressionEvaluator::m_function2

private

Definition at line 460 of file AnalyticExpressionEvaluator.hpp.

Referenced by AnalyticExpressionEvaluator(), and PrepareExecutionAsYouParse().

FunctionNameMap Nektar::LibUtilities::AnalyticExpressionEvaluator::m_functionMapNameToInstanceType

private

Definition at line 458 of file AnalyticExpressionEvaluator.hpp.

Referenced by AnalyticExpressionEvaluator(), and PrepareExecutionAsYouParse().

RandomGeneratorType Nektar::LibUtilities::AnalyticExpressionEvaluator::m_generator

private

Definition at line 447 of file AnalyticExpressionEvaluator.hpp.

Referenced by SetRandomSeed().

std::vector<NekDouble> Nektar::LibUtilities::AnalyticExpressionEvaluator::m_parameter

private

Definition at line 425 of file AnalyticExpressionEvaluator.hpp.

Referenced by GetParameter(), and SetParameter().

ParameterMap Nektar::LibUtilities::AnalyticExpressionEvaluator::m_parameterMapNameToId

private

The following data structures hold input data to be used on evaluation stage. There are three types of input data:

• constants (never change their value)
• parameters are allowed to change their values between evaluations (compared to constants)
• variables always change their values at every evaluation call. First map looks like <parameter_name, parameter_id> while the second is <parameter_id, parameter_value>. The map is used at a preparation stage when the analytic expression is parsed. This associates an integer id with a parameter name in its string form. On evaluation stage the id and a std::vector constant lookup time make evaluation faster compared to permanent std::map<std::string, NekDouble> lookup.

Definition at line 421 of file AnalyticExpressionEvaluator.hpp.

Referenced by GetParameter(), PrepareExecutionAsYouParse(), and SetParameter().

ExpressionMap Nektar::LibUtilities::AnalyticExpressionEvaluator::m_parsedMapExprToExecStackId

private

These vector and map store pre-processed evaluation sequences for the analytic expressions. Each ExecutionStack is an ordered container of steps of sequential execution process which evaluates an analytic expression.

Definition at line 395 of file AnalyticExpressionEvaluator.hpp.

Referenced by DefineFunction().

std::vector<VariableMap> Nektar::LibUtilities::AnalyticExpressionEvaluator::m_stackVariableMap

private

Keeping map of variables individually per each analytic expression allows correctly handling expressions which depend on different number of variables.

Definition at line 402 of file AnalyticExpressionEvaluator.hpp.

Referenced by DefineFunction(), and EvaluateAtPoint().

std::vector<NekDouble> Nektar::LibUtilities::AnalyticExpressionEvaluator::m_state

private

This vector stores the execution state (memory) used by the sequential execution process.

Definition at line 432 of file AnalyticExpressionEvaluator.hpp.

Referenced by Evaluate(), and EvaluateAtPoint().

int Nektar::LibUtilities::AnalyticExpressionEvaluator::m_state_size

private

This counter is used by PrepareExecutionAsYouParse for finding the minimal state size necessary for evaluation of function parsed.

Definition at line 439 of file AnalyticExpressionEvaluator.hpp.

Referenced by AnalyticExpressionEvaluator(), DefineFunction(), and PrepareExecutionAsYouParse().

std::vector<int> Nektar::LibUtilities::AnalyticExpressionEvaluator::m_state_sizes

private

Vector of state sizes per each.

Definition at line 435 of file AnalyticExpressionEvaluator.hpp.

Referenced by DefineFunction(), Evaluate(), and EvaluateAtPoint().

Timer Nektar::LibUtilities::AnalyticExpressionEvaluator::m_timer

private

Timer and sum of evaluation times.

Definition at line 443 of file AnalyticExpressionEvaluator.hpp.

Referenced by Evaluate(), and EvaluateAtPoint().

NekDouble Nektar::LibUtilities::AnalyticExpressionEvaluator::m_total_eval_time

private

Definition at line 444 of file AnalyticExpressionEvaluator.hpp.

Referenced by Evaluate(), EvaluateAtPoint(), and GetTime().

std::vector<NekDouble> Nektar::LibUtilities::AnalyticExpressionEvaluator::m_variable

private

Definition at line 427 of file AnalyticExpressionEvaluator.hpp.

Referenced by Evaluate(), and EvaluateAtPoint().