Description

template<std::size_t numVars, class Scalar = double>
class Dumux::FunctionFromStringExpression< numVars, Scalar >

Template Parameters

numVars	number of variables in the expression; number of function arguments of the call operator
Scalar	type of numerical values in the expression

Example usage

// Create a callable f(x,t) from a string expression containing variable literals.
// The constructor compiles the expression in the constructor making calls efficient.
// The constructor throws a Dune::IOError with detailed info if parsing fails.
std::string expr = getParam("Problem.Function"); // e.g. "5*x + x*sin(x*t)"
FunctionFromStringExpression<2> f(expr, "xt"); // variables "x" and "t"
 
// evaluate function, result is double (the default scalar type)
const double x = 1.0, t = 2.0;
const double result = f(x, t);

For variables with several characters construct

// variables "pos" and "time"

FunctionFromStringExpression<2> f(expr, std::array<std::string, 2>{{"pos", "time"}});

Public Member Functions
	FunctionFromStringExpression (const std::string &expression, const std::array< std::string, numVars > &variableNames)
	Constructor from math expression and array of variable names. More...

	FunctionFromStringExpression (const std::string &expression, std::string_view variableNames)
	Delegating constructor using all characters of a string as variables. More...

template<class S , std::enable_if_t< std::is_convertible_v< Scalar, S >, int > = 0>
Scalar	operator() (const std::array< S, numVars > &params) const

template<class S , std::enable_if_t< std::is_convertible_v< Scalar, S >, int > = 0>
Scalar	operator() (const Dune::FieldVector< S, numVars > &params) const

template<class ... Params, std::enable_if_t<(sizeof...(Params)==numVars) &&(std::is_convertible_v< Scalar, std::decay_t< Params > > &&...), int > = 0>
Scalar	operator() (Params &&... params) const

void	setVerbosity (unsigned int v)

Static Public Attributes
static constexpr std::size_t	numVariables = numVars