Interprets mathematical expressions in a string and evaluates them using Kokkos::View objects as values and Kokkos::parallel_for for the operators. This class is mean to support Kokkos-parallel execution of user-provided mathematical expressions. Example uses include evaluating analytic boundary and initial conditions for a PDE problem. The API of this class (namely Eval::read_string or another read_* function inherited from Teuchos::Reader) is only meant to be called once for a given set of evaluation points. Variables should be predefined with point-dependent values all stored in a single Kokkos::View. For example, X coordinates for all points could be stored in a Kokkos::View<double*>, whose extent is the number of points. Values which are the same for all points are still supported, for example the current time. Then if the expression is for example "x^t", this class launches a single parallel_for to raise the coordinate of all points at once to the "t" power. More...

#include <Panzer_ExprEval.hpp>

Inheritance diagram for panzer::Expr::Eval< DT, VP >:

[legend]

Public Types
using	original_view_type = Kokkos::View< DT, VP...>
	The corresponding Kokkos::View type, using the same template arguments are were given to Eval. More...

using	view_data_type = DT
	The data type, including dimension information. More...

using	scalar_type = typename original_view_type::non_const_value_type
	The scalar type. More...

using	const_view_type = Kokkos::View< typename RebindDataType< view_data_type, scalar_type const >::type, VP...>
	One scalar for each evaluation point, read-only. More...

using	const_bool_view_type = Kokkos::View< typename RebindDataType< view_data_type, bool const >::type, VP...>
	One boolean for each evaluation point, read-only. More...

using	single_view_type = Kokkos::View< scalar_type, VP...>
	One scalar (same for all evaluation points) More...

using	const_single_view_type = Kokkos::View< scalar_type const, VP...>
	One scalar (same for all evaluation points), read-only. More...

using	single_bool_view_type = Kokkos::View< bool, VP...>
	One boolean (same for all evaluation points) More...

using	const_single_bool_view_type = Kokkos::View< bool const, VP...>
	One boolean (same for all evaluation points), read-only. More...

Public Types inherited from panzer::Expr::EvalBase
using	Function = std::function< void(std::string const &name, Teuchos::any &, std::vector< Teuchos::any > &rhs)>
	The type of user-defined functions which are callable in the math language. More...

Public Member Functions
	Eval ()

void	set (std::string const &name, bool value)
	Assign a boolean value to a variable symbol. More...

void	set (std::string const &name, scalar_type const &value)
	Assign a scalar value to a variable symbol. More...

void	set (std::string const &name, const_view_type const &value)
	Assign scalar values (one for each evaluation point) to a variable symbol. More...

Public Member Functions inherited from panzer::Expr::EvalBase
	EvalBase ()
	Constructor. More...

void	set (std::string const &name, Function const &value)
	Registers an EvalBase::Function, binding it to a name and making it callable. More...

template<typename T >
T const &	get (std::string const &name) const
	Get the value of a variable in the symbol map. More...

Public Member Functions inherited from Teuchos::Reader
virtual	~Reader ()

	Reader (ReaderTablesPtr tables_in)

void	read_stream (any &result, std::istream &stream, std::string const &stream_name_in)

void	read_string (any &result, std::string const &string, std::string const &string_name)

void	read_file (any &result, std::string const &file_name)

Protected Member Functions
void	make_constant (Teuchos::any &result, double const &value) override

void	inspect_arg (Teuchos::any const &arg, bool &is_many, bool &is_bool) override

void	single_single_ternary_op (Teuchos::any &result, Teuchos::any &cond, Teuchos::any &left, Teuchos::any &right) override

void	single_many_ternary_op (Teuchos::any &result, Teuchos::any &cond, Teuchos::any &left, Teuchos::any &right) override

void	many_single_ternary_op (Teuchos::any &result, Teuchos::any &cond, Teuchos::any &left, Teuchos::any &right) override

void	many_many_ternary_op (Teuchos::any &result, Teuchos::any &cond, Teuchos::any &left, Teuchos::any &right) override

void	single_single_binary_op (BinaryOpCode code, Teuchos::any &result, Teuchos::any &left, Teuchos::any &right) override

void	single_many_binary_op (BinaryOpCode code, Teuchos::any &result, Teuchos::any &left, Teuchos::any &right) override

void	many_single_binary_op (BinaryOpCode code, Teuchos::any &result, Teuchos::any &left, Teuchos::any &right) override

void	many_many_binary_op (BinaryOpCode code, Teuchos::any &result, Teuchos::any &left, Teuchos::any &right) override

void	many_neg_op (Teuchos::any &result, Teuchos::any &right) override

void	single_neg_op (Teuchos::any &result, Teuchos::any &right) override

Protected Member Functions inherited from panzer::Expr::EvalBase
void	at_shift (Teuchos::any &result, int token, std::string &text) override
	Called at every parsed token in the math language. More...

void	at_reduce (Teuchos::any &result, int prod, std::vector< Teuchos::any > &rhs) override
	Called at every reduced production in the math language. More...

void	ternary_op (Teuchos::any &result, Teuchos::any &cond, Teuchos::any &left, Teuchos::any &right)
	Executes the ternary operator, e.g. (a > b) ? a : b. More...

void	binary_op (BinaryOpCode code, Teuchos::any &result, Teuchos::any &left, Teuchos::any &right)
	Executes a binary operator. More...

void	neg_op (Teuchos::any &result, Teuchos::any &right)
	Executes the only native unary operator in the math language, numeric negation via a minus sign. More...

Additional Inherited Members
Protected Attributes inherited from panzer::Expr::EvalBase
std::map< std::string, Teuchos::any >	symbol_map
	Stores all current symbols including variables and functions. More...

Detailed Description

template<typename DT, typename... VP>
class panzer::Expr::Eval< DT, VP >

Interprets mathematical expressions in a string and evaluates them using Kokkos::View objects as values and Kokkos::parallel_for for the operators. This class is mean to support Kokkos-parallel execution of user-provided mathematical expressions. Example uses include evaluating analytic boundary and initial conditions for a PDE problem. The API of this class (namely Eval::read_string or another read_* function inherited from Teuchos::Reader) is only meant to be called once for a given set of evaluation points. Variables should be predefined with point-dependent values all stored in a single Kokkos::View. For example, X coordinates for all points could be stored in a Kokkos::View<double*>, whose extent is the number of points. Values which are the same for all points are still supported, for example the current time. Then if the expression is for example "x^t", this class launches a single parallel_for to raise the coordinate of all points at once to the "t" power.

Note

This class currently supports rank-1 and rank-2 Kokkos::Views. It should support all scalar types which support the native binary operators ('+', '-', '*', '/'), and also pow(x, y).

Expression results are allocated when an expression is evaluated, and deallocated after they have been used in all higher-level expressions. For example, "(a * b) + c" does the following:

allocate space for "(a * b)"
compute and store "(a * b)"
allocate space for "(a * b) + c"
compute and store "(a * b) + c"
deallocate space for "(a * b)"

Definition at line 229 of file Panzer_ExprEval.hpp.

Member Typedef Documentation

template<typename DT, typename... VP>

using panzer::Expr::Eval< DT, VP >::original_view_type = Kokkos::View<DT, VP ...>

The corresponding Kokkos::View type, using the same template arguments are were given to Eval.

Definition at line 232 of file Panzer_ExprEval.hpp.

template<typename DT, typename... VP>

using panzer::Expr::Eval< DT, VP >::view_data_type = DT

The data type, including dimension information.

Definition at line 234 of file Panzer_ExprEval.hpp.

template<typename DT, typename... VP>

using panzer::Expr::Eval< DT, VP >::scalar_type = typename original_view_type::non_const_value_type

The scalar type.

This type should be constructible from a value of type "double" and should be usable with the four basic binary operator ('+', '-', '*', '/') and also the pow() function.

Definition at line 241 of file Panzer_ExprEval.hpp.

template<typename DT, typename... VP>

using panzer::Expr::Eval< DT, VP >::const_view_type = Kokkos::View<typename RebindDataType<view_data_type, scalar_type const>::type, VP ...>

One scalar for each evaluation point, read-only.

This is the original view type where the scalar type is constant. This means it is a read-only view. and will most likely be the type that is returned from read_string().

Definition at line 249 of file Panzer_ExprEval.hpp.

template<typename DT, typename... VP>

using panzer::Expr::Eval< DT, VP >::const_bool_view_type = Kokkos::View<typename RebindDataType<view_data_type, bool const>::type, VP ...>

One boolean for each evaluation point, read-only.

Definition at line 253 of file Panzer_ExprEval.hpp.

template<typename DT, typename... VP>

using panzer::Expr::Eval< DT, VP >::single_view_type = Kokkos::View<scalar_type, VP ...>

One scalar (same for all evaluation points)

Definition at line 257 of file Panzer_ExprEval.hpp.

template<typename DT, typename... VP>

using panzer::Expr::Eval< DT, VP >::const_single_view_type = Kokkos::View<scalar_type const, VP ...>

One scalar (same for all evaluation points), read-only.

Definition at line 261 of file Panzer_ExprEval.hpp.

template<typename DT, typename... VP>

using panzer::Expr::Eval< DT, VP >::single_bool_view_type = Kokkos::View<bool, VP ...>

One boolean (same for all evaluation points)

Definition at line 265 of file Panzer_ExprEval.hpp.

template<typename DT, typename... VP>

using panzer::Expr::Eval< DT, VP >::const_single_bool_view_type = Kokkos::View<bool const, VP ...>

One boolean (same for all evaluation points), read-only.

Definition at line 269 of file Panzer_ExprEval.hpp.