*
* The following examples shows how to use this class:
* @code
- // set up problem:
- std::string variables = "x,y";
- std::string expression = "cos(x)+sqrt(y)";
- std::map<std::string,double> constants;
-
- // FunctionParser with 2 variables and 1 component:
- FunctionParser<2> fp(1);
- fp.initialize(variables,
- expression,
- constants);
-
- // Point at which we want to evaluate the function
- Point<2> point(0.0, 4.0);
-
- // evaluate the expression at 'point':
- double result = fp.value(point);
-
- deallog << "Function '" << expression << "'"
- << " @ " << point
- << " is " << result << std::endl;
-@endcode
-* The second example is a bit more complex:
-* @code
- // Define some constants that will be used by the function parser
- std::map<std::string,double> constants;
- constants["pi"] = numbers::PI;
-
- // Define the variables that will be used inside the expressions
- std::string variables = "x,y,z";
-
- // Define the expressions of the individual components of a
- // vector valued function with two components:
- std::vector<std::string> expressions(2);
- expressions[0] = "sin(2*pi*x)+sinh(pi*z)";
- expressions[1] = "sin(2*pi*y)*exp(x^2)";
-
- // function parser with 3 variables and 2 components
- FunctionParser<3> vector_function(2);
-
- // And populate it with the newly created objects.
- vector_function.initialize(variables,
- expressions,
- constants);
-
- // Point at which we want to evaluate the function
- Point<3> point(0.0, 1.0, 1.0);
-
- // This Vector will store the result
- Vector<double> result(2);
-
- // Fill 'result' by evaluating the function
- vector_function.vector_value(point, result);
-
- // We can also only evaluate the 2nd component:
- double c = vector_function.value(point, 1);
-
- // Output the evaluated function
- deallog << "Function '" << expressions[0] << "," << expressions[1] << "'"
- << " @ " << point
- << " is " << result << std::endl;
- * @endcode
- *
- * This class overloads the virtual methods value() and
- * vector_value() of the Function base class with the byte compiled versions
- * of the expressions given to the initialize() methods. Note that the class
- * will not work unless you first call the initialize() method that accepts
- * the text description of the function as an argument (among other
- * things).
- *
- * The syntax to describe a function follows usual programming practice,
- * and is explained in this snippet from the fparser.txt file:
- @verbatim
- The function string understood by the class is very similar to the C-syntax.
- Arithmetic float expressions can be created from float literals, variables
- or functions using the following operators in this order of precedence:
-
- -A unary minus
- A^B exponentiation (A raised to the power B)
- A*B A/B A%B multiplication, division and modulo
- A+B A-B addition and subtraction
- A==B A<B A>B comparison between A and B (result is either 0 or 1)
- A&&B A||B logical 'and' and 'or'
- A&B A|B same, implemented for compatibility
-
- Since the unary minus has higher precedence than any other operator, for
- example the following expression is valid: x*-y
-
- Note that the '==' comparison can be inaccurate due to floating point
- precision problems, so it should be avoided (eg. "sqrt(100)=10" probably
- returns 0, not 1).
-
- The class supports these functions:
-
- abs(A) : Absolute value of A. If A is negative, returns -A otherwise
- returns A.
- acos(A) : Arc-cosine of A. Returns the angle, measured in radians,
- whose cosine is A.
- acosh(A) : Same as acos() but for hyperbolic cosine.
- asin(A) : Arc-sine of A. Returns the angle, measured in radians, whose
- sine is A.
- asinh(A) : Same as asin() but for hyperbolic sine.
- atan(A) : Arc-tangent of (A). Returns the angle, measured in radians,
- whose tangent is (A).
- atan2(A,B): Arc-tangent of A/B. The two main differences to atan() is
- that it will return the right angle depending on the signs of
- A and B (atan() can only return values between -pi/2 and pi/2),
- and that the return value of pi/2 and -pi/2 are possible.
- atanh(A) : Same as atan() but for hyperbolic tangent.
- ceil(A) : Ceiling of A. Returns the smallest integer greater than A.
- Rounds up to the next higher integer.
- cos(A) : Cosine of A. Returns the cosine of the angle A, where A is
- measured in radians.
- cosh(A) : Same as cos() but for hyperbolic cosine.
- cot(A) : Cotangent of A (equivalent to 1/tan(A)).
- csc(A) : Cosecant of A (equivalent to 1/sin(A)).
- exp(A) : Exponential of A. Returns the value of e raised to the power
- A where e is the base of the natural logarithm, i.e. the
- non-repeating value approximately equal to 2.71828182846.
- floor(A) : Floor of A. Returns the largest integer less than A. Rounds
- down to the next lower integer.
- if(A,B,C) : If int(A) differs from 0, the return value of this function is B,
- else C. Only the parameter which needs to be evaluated is
- evaluated, the other parameter is skipped; this makes it safe to
- use eval() in them.
- int(A) : Rounds A to the closest integer. 0.5 is rounded to 1.
- log(A) : Natural (base e) logarithm of A.
- log10(A) : Base 10 logarithm of A.
- max(A,B) : If A>B, the result is A, else B.
- min(A,B) : If A<B, the result is A, else B.
- sec(A) : Secant of A (equivalent to 1/cos(A)).
- sin(A) : Sine of A. Returns the sine of the angle A, where A is
- measured in radians.
- sinh(A) : Same as sin() but for hyperbolic sine.
- sqrt(A) : Square root of A. Returns the value whose square is A.
- tan(A) : Tangent of A. Returns the tangent of the angle A, where A
- is measured in radians.
- tanh(A) : Same as tan() but for hyperbolic tangent.
-
-
- Examples of function string understood by the class:
-
- "1+2"
- "x-1"
- "-sin(sqrt(x^2+y^2))"
- "sqrt(XCoord*XCoord + YCoord*YCoord)"
-
- @endverbatim
+ * // set up problem:
+ * std::string variables = "x,y";
+ * std::string expression = "cos(x)+sqrt(y)";
+ * std::map<std::string,double> constants;
+ *
+ * // FunctionParser with 2 variables and 1 component:
+ * FunctionParser<2> fp(1);
+ * fp.initialize(variables,
+ * expression,
+ * constants);
+ *
+ * // Point at which we want to evaluate the function
+ * Point<2> point(0.0, 4.0);
+ *
+ * // evaluate the expression at 'point':
+ * double result = fp.value(point);
+ *
+ * deallog << "Function '" << expression << "'"
+ * << " @ " << point
+ * << " is " << result << std::endl;
+ * @endcode
+ * The second example is a bit more complex:
+ * @code
+ * // Define some constants that will be used by the function parser
+ * std::map<std::string,double> constants;
+ * constants["pi"] = numbers::PI;
+ *
+ * // Define the variables that will be used inside the expressions
+ * std::string variables = "x,y,z";
+ *
+ * // Define the expressions of the individual components of a
+ * // vector valued function with two components:
+ * std::vector<std::string> expressions(2);
+ * expressions[0] = "sin(2*pi*x)+sinh(pi*z)";
+ * expressions[1] = "sin(2*pi*y)*exp(x^2)";
+ *
+ * // function parser with 3 variables and 2 components
+ * FunctionParser<3> vector_function(2);
+ *
+ * // And populate it with the newly created objects.
+ * vector_function.initialize(variables,
+ * expressions,
+ * constants);
+ *
+ * // Point at which we want to evaluate the function
+ * Point<3> point(0.0, 1.0, 1.0);
+ *
+ * // This Vector will store the result
+ * Vector<double> result(2);
+ *
+ * // Fill 'result' by evaluating the function
+ * vector_function.vector_value(point, result);
+ *
+ * // We can also only evaluate the 2nd component:
+ * double c = vector_function.value(point, 1);
+ *
+ * // Output the evaluated function
+ * deallog << "Function '" << expressions[0] << "," << expressions[1] << "'"
+ * << " @ " << point
+ * << " is " << result << std::endl;
+ * @endcode
+ *
+ * This class overloads the virtual methods value() and vector_value() of the
+ * Function base class with the byte compiled versions of the expressions
+ * given to the initialize() methods. Note that the class will not work unless
+ * you first call the initialize() method that accepts the text description of
+ * the function as an argument (among other things).
+ *
+ * The syntax to describe a function follows usual programming practice, and
+ * is explained in this snippet from the fparser.txt file:
+ * @verbatim
+ * The function string understood by the class is very similar to the C-syntax.
+ * Arithmetic float expressions can be created from float literals, variables
+ * or functions using the following operators in this order of precedence:
+ *
+ * -A unary minus
+ * A^B exponentiation (A raised to the power B)
+ * A*B A/B A%B multiplication, division and modulo
+ * A+B A-B addition and subtraction
+ * A==B A<B A>B comparison between A and B (result is either 0 or 1)
+ * A&&B A||B logical 'and' and 'or'
+ * A&B A|B same, implemented for compatibility
+ *
+ * Since the unary minus has higher precedence than any other operator, for
+ * example the following expression is valid: x*-y
+ *
+ * Note that the '==' comparison can be inaccurate due to floating point
+ * precision problems, so it should be avoided (eg. "sqrt(100)=10" probably
+ * returns 0, not 1).
+ *
+ * The class supports these functions:
+ *
+ * abs(A) : Absolute value of A. If A is negative, returns -A otherwise
+ * returns A.
+ * acos(A) : Arc-cosine of A. Returns the angle, measured in radians,
+ * whose cosine is A.
+ * acosh(A) : Same as acos() but for hyperbolic cosine.
+ * asin(A) : Arc-sine of A. Returns the angle, measured in radians, whose
+ * sine is A.
+ * asinh(A) : Same as asin() but for hyperbolic sine.
+ * atan(A) : Arc-tangent of (A). Returns the angle, measured in radians,
+ * whose tangent is (A).
+ * atan2(A,B): Arc-tangent of A/B. The two main differences to atan() is
+ * that it will return the right angle depending on the signs of
+ * A and B (atan() can only return values between -pi/2 and pi/2),
+ * and that the return value of pi/2 and -pi/2 are possible.
+ * atanh(A) : Same as atan() but for hyperbolic tangent.
+ * ceil(A) : Ceiling of A. Returns the smallest integer greater than A.
+ * Rounds up to the next higher integer.
+ * cos(A) : Cosine of A. Returns the cosine of the angle A, where A is
+ * measured in radians.
+ * cosh(A) : Same as cos() but for hyperbolic cosine.
+ * cot(A) : Cotangent of A (equivalent to 1/tan(A)).
+ * csc(A) : Cosecant of A (equivalent to 1/sin(A)).
+ * exp(A) : Exponential of A. Returns the value of e raised to the power
+ * A where e is the base of the natural logarithm, i.e. the
+ * non-repeating value approximately equal to 2.71828182846.
+ * floor(A) : Floor of A. Returns the largest integer less than A. Rounds
+ * down to the next lower integer.
+ * if(A,B,C) : If int(A) differs from 0, the return value of this function is B,
+ * else C. Only the parameter which needs to be evaluated is
+ * evaluated, the other parameter is skipped; this makes it safe to
+ * use eval() in them.
+ * int(A) : Rounds A to the closest integer. 0.5 is rounded to 1.
+ * log(A) : Natural (base e) logarithm of A.
+ * log10(A) : Base 10 logarithm of A.
+ * max(A,B) : If A>B, the result is A, else B.
+ * min(A,B) : If A<B, the result is A, else B.
+ * sec(A) : Secant of A (equivalent to 1/cos(A)).
+ * sin(A) : Sine of A. Returns the sine of the angle A, where A is
+ * measured in radians.
+ * sinh(A) : Same as sin() but for hyperbolic sine.
+ * sqrt(A) : Square root of A. Returns the value whose square is A.
+ * tan(A) : Tangent of A. Returns the tangent of the angle A, where A
+ * is measured in radians.
+ * tanh(A) : Same as tan() but for hyperbolic tangent.
+ *
+ *
+ * Examples of function string understood by the class:
+ *
+ * "1+2"
+ * "x-1"
+ * "-sin(sqrt(x^2+y^2))"
+ * "sqrt(XCoord*XCoord + YCoord*YCoord)"
+ *
+ * @endverbatim
*
* Vector-valued functions can either be declared using strings where the
* function components are separated by semicolons, or using a vector of
* strings each defining one vector component.
*
* An example of time dependent scalar function is the following:
- @code
-
- // Empty constants object
- std::map<std::string> constants;
-
- // Variables that will be used inside the expressions
- std::string variables = "x,y,t";
-
- // Define the expression of the scalar time dependent function.
- std::string expression = "exp(y*x)*exp(-t)";
-
- // Generate an empty scalar function
- FunctionParser<2> function;
-
- // And populate it with the newly created objects.
- function.initialize(variables,
- expression,
- constants,
- true); // This tells the parser that
- // it is a time-dependent function
- // and there is another variable
- // to be taken into account (t).
-
- @endcode
-
- * The following is another example of how to instantiate a
- * vector valued function by using a single string:
- @code
-
- // Empty constants object
- std::map<std::string> constants;
-
- // Variables that will be used inside the expressions
- std::string variables = "x,y";
-
- // Define the expression of the vector valued function.
- std::string expression = "cos(2*pi*x)*y^2; sin(2*pi*x)*exp(y)";
-
- // Generate an empty vector valued function
- FunctionParser<2> function(2);
-
- // And populate it with the newly created objects.
- function.initialize(variables,
- expression,
- constants);
-
- @endcode
+ * @code
+ *
+ * // Empty constants object
+ * std::map<std::string> constants;
+ *
+ * // Variables that will be used inside the expressions
+ * std::string variables = "x,y,t";
+ *
+ * // Define the expression of the scalar time dependent function.
+ * std::string expression = "exp(y*x)*exp(-t)";
+ *
+ * // Generate an empty scalar function
+ * FunctionParser<2> function;
+ *
+ * // And populate it with the newly created objects.
+ * function.initialize(variables,
+ * expression,
+ * constants,
+ * true); // This tells the parser that
+ * // it is a time-dependent function
+ * // and there is another variable
+ * // to be taken into account (t).
+ *
+ * @endcode
+ *
+ * The following is another example of how to instantiate a vector valued
+ * function by using a single string:
+ * @code
+ *
+ * // Empty constants object
+ * std::map<std::string> constants;
+ *
+ * // Variables that will be used inside the expressions
+ * std::string variables = "x,y";
+ *
+ * // Define the expression of the vector valued function.
+ * std::string expression = "cos(2*pi*x)*y^2; sin(2*pi*x)*exp(y)";
+ *
+ * // Generate an empty vector valued function
+ * FunctionParser<2> function(2);
+ *
+ * // And populate it with the newly created objects.
+ * function.initialize(variables,
+ * expression,
+ * constants);
+ *
+ * @endcode
*
*
* @ingroup functions
template <int dim>
class FunctionParser : public Function<dim>
{
-public:
- /**
- * Constructor for Parsed
- * functions. Its arguments are
- * the same of the base class
- * Function. The only difference
- * is that this object needs to
- * be initialized with
- * initialize() method before you
- * can use it. If an attempt to
- * use this function is made
- * before the initialize() method
- * has been called, then an
- * exception is thrown.
- */
- FunctionParser (const unsigned int n_components = 1,
- const double initial_time = 0.0);
-
- /**
- * Destructor. Explicitly delete
- * the FunctionParser objects
- * (there is one for each
- * component of the function).
- */
- ~FunctionParser();
-
- /**
- * Type for the constant
- * map. Used by the initialize()
- * method.
- */
- typedef std::map<std::string, double> ConstMap;
-
- /**
- * Iterator for the constants
- * map. Used by the initialize()
- * method.
- */
- typedef ConstMap::iterator ConstMapIterator;
-
- /**
- * Initialize the function. This methods
- * accepts the following parameters:
- *
- * <b>vars</b>: a string with
- * the variables that will be used by the
- * expressions to be evaluated. Note that
- * the variables can have any name (of
- * course different from the function
- * names defined above!), but the order
- * IS important. The first variable will
- * correspond to the first component of
- * the point in which the function is
- * evaluated, the second variable to the
- * second component and so forth. If this
- * function is also time dependent, then
- * it is necessary to specify it by
- * setting the <tt>time_dependent</tt> parameter
- * to true. An exception is thrown if
- * the number of variables specified here
- * is different from dim (if this
- * function is not time-dependent) or
- * from dim+1 (if it is time-dependent).
- *
- * <b>expressions</b>: a list of strings
- * containing the expressions that will
- * be byte compiled by the internal
- * parser (FunctionParser). Note that the
- * size of this vector must match exactly
- * the number of components of the
- * FunctionParser, as declared in the
- * constructor. If this is not the case,
- * an exception is thrown.
- *
- *
- * <b>constants</b>: a map of constants
- * used to pass any necessary constant
- * that we want to specify in our
- * expressions (in the example above the
- * number pi). An expression is valid if
- * and only if it contains only defined
- * variables and defined constants (other
- * than the functions specified
- * above). If a constant is given whose
- * name is not valid (eg:
- * <tt>constants["sin"] = 1.5;</tt>) an
- * exception is thrown.
- *
- * <b>time_dependent</b>. If this is a
- * time dependent function, then the last
- * variable declared in <b>vars</b> is
- * assumed to be the time variable, and
- * this->get_time() is used to initialize
- * it when evaluating the
- * function. Naturally the number of
- * variables parsed by the initialize()
- * method in this case is dim+1. The
- * value of this parameter defaults to
- * false, i.e. do not consider time.
- */
- void initialize (const std::string &vars,
- const std::vector<std::string> &expressions,
- const ConstMap &constants,
- const bool time_dependent = false);
+ public:
+ /**
+ * Constructor for Parsed functions. Its arguments are the same of the
+ * base class Function. The only difference is that this object needs to
+ * be initialized with initialize() method before you can use it. If an
+ * attempt to use this function is made before the initialize() method has
+ * been called, then an exception is thrown.
+ */
+ FunctionParser (const unsigned int n_components = 1,
+ const double initial_time = 0.0);
+
+ /**
+ * Destructor. Explicitly delete the FunctionParser objects (there is one
+ * for each component of the function).
+ */
+ ~FunctionParser();
+
+ /**
+ * Type for the constant map. Used by the initialize() method.
+ */
+ typedef std::map<std::string, double> ConstMap;
+
+ /**
+ * Iterator for the constants map. Used by the initialize() method.
+ */
+ typedef ConstMap::iterator ConstMapIterator;
/**
- * Same as above, but with an additional parameter:
- * <b>use_degrees</b>. Parameter to decide if the trigonometric functions
- * work in radians or degrees. The default for this parameter is false,
- * i.e. use radians and not degrees.
+ * Initialize the function. This methods accepts the following
+ * parameters:
+ *
+ * <b>vars</b>: a string with the variables that will be used by the
+ * expressions to be evaluated. Note that the variables can have any name
+ * (of course different from the function names defined above!), but the
+ * order IS important. The first variable will correspond to the first
+ * component of the point in which the function is evaluated, the second
+ * variable to the second component and so forth. If this function is also
+ * time dependent, then it is necessary to specify it by setting the
+ * <tt>time_dependent</tt> parameter to true. An exception is thrown if
+ * the number of variables specified here is different from dim (if this
+ * function is not time-dependent) or from dim+1 (if it is time-
+ * dependent).
+ *
+ * <b>expressions</b>: a list of strings containing the expressions that
+ * will be byte compiled by the internal parser (FunctionParser). Note
+ * that the size of this vector must match exactly the number of
+ * components of the FunctionParser, as declared in the constructor. If
+ * this is not the case, an exception is thrown.
+ *
+ *
+ * <b>constants</b>: a map of constants used to pass any necessary
+ * constant that we want to specify in our expressions (in the example
+ * above the number pi). An expression is valid if and only if it contains
+ * only defined variables and defined constants (other than the functions
+ * specified above). If a constant is given whose name is not valid (eg:
+ * <tt>constants["sin"] = 1.5;</tt>) an exception is thrown.
+ *
+ * <b>time_dependent</b>. If this is a time dependent function, then the
+ * last variable declared in <b>vars</b> is assumed to be the time
+ * variable, and this->get_time() is used to initialize it when evaluating
+ * the function. Naturally the number of variables parsed by the
+ * initialize() method in this case is dim+1. The value of this parameter
+ * defaults to false, i.e. do not consider time.
+ */
+ void initialize (const std::string &vars,
+ const std::vector<std::string> &expressions,
+ const ConstMap &constants,
+ const bool time_dependent = false);
+
+ /**
+ * Same as above, but with an additional parameter: <b>use_degrees</b>.
+ * Parameter to decide if the trigonometric functions work in radians or
+ * degrees. The default for this parameter is false, i.e. use radians and
+ * not degrees.
*
* @note: this function is deprecated. Use the function without this
* argument instead (which has the default use_degrees=false).
*/
void initialize (const std::string &vars,
- const std::vector<std::string> &expressions,
- const ConstMap &constants,
- const bool time_dependent,
- const bool use_degrees) DEAL_II_DEPRECATED;
-
-
- /**
- * Initialize the function. Same as
- * above, but with an additional argument
- * <b> units </b> - a map of units passed to
- * FunctionParser via AddUnint.
- *
- * Can be used as "3cm".
- * Have higher precedence in parsing, i.e.
- * if cm=10 then 3/2cm is 3 /(2*10).
- * See contrib/functionparser/fparser.txt
- * for more details.
- */
- void initialize (const std::string &vars,
- const std::vector<std::string> &expressions,
- const ConstMap &constants,
- const ConstMap &units,
- const bool time_dependent = false,
- const bool use_degrees = false) DEAL_II_DEPRECATED;
-
- /**
- * Initialize the function. Same as
- * above, but accepts a string rather
- * than a vector of strings. If this is a
- * vector valued function, its
- * components are expected to be
- * separated by a semicolon. An exception
- * is thrown if this method is called and
- * the number of components successfully
- * parsed does not match the number of
- * components of the base function.
- */
- void initialize (const std::string &vars,
- const std::string &expression,
- const ConstMap &constants,
- const bool time_dependent = false);
+ const std::vector<std::string> &expressions,
+ const ConstMap &constants,
+ const bool time_dependent,
+ const bool use_degrees) DEAL_II_DEPRECATED;
+
/**
- * Same as above, but with an additional parameter:
- * <b>use_degrees</b>. Parameter to decide if the trigonometric functions
- * work in radians or degrees. The default for this parameter is false,
- * i.e. use radians and not degrees.
+ * Initialize the function. Same as above, but with an additional argument
+ * <b> units </b> - a map of units passed to FunctionParser via AddUnint.
+ *
+ * Can be used as "3cm". Have higher precedence in parsing, i.e. if cm=10
+ * then 3/2cm is 3 /(2*10). See contrib/functionparser/fparser.txt for
+ * more details.
+ */
+ void initialize (const std::string &vars,
+ const std::vector<std::string> &expressions,
+ const ConstMap &constants,
+ const ConstMap &units,
+ const bool time_dependent = false,
+ const bool use_degrees = false) DEAL_II_DEPRECATED;
+
+ /**
+ * Initialize the function. Same as above, but accepts a string rather
+ * than a vector of strings. If this is a vector valued function, its
+ * components are expected to be separated by a semicolon. An exception is
+ * thrown if this method is called and the number of components
+ * successfully parsed does not match the number of components of the base
+ * function.
+ */
+ void initialize (const std::string &vars,
+ const std::string &expression,
+ const ConstMap &constants,
+ const bool time_dependent = false);
+
+ /**
+ * Same as above, but with an additional parameter: <b>use_degrees</b>.
+ * Parameter to decide if the trigonometric functions work in radians or
+ * degrees. The default for this parameter is false, i.e. use radians and
+ * not degrees.
*
* @note: this function is deprecated. Use the function without this
* argument instead (which has the default use_degrees=false).
*/
- void initialize (const std::string &vars,
- const std::string &expression,
- const ConstMap &constants,
- const bool time_dependent,
- const bool use_degrees) DEAL_II_DEPRECATED;
- /**
- * Initialize the function. Same as
- * above, but with <b>units</b>.
- */
-
- void initialize (const std::string &vars,
- const std::string &expression,
- const ConstMap &constants,
- const ConstMap &units,
- const bool time_dependent = false,
- const bool use_degrees = false) DEAL_II_DEPRECATED;
-
- /**
- * A function that returns
- * default names for variables,
- * to be used in the first
- * argument of the initialize()
- * functions: it returns "x" in
- * 1d, "x,y" in 2d, and "x,y,z"
- * in 3d.
- */
- static
- std::string
- default_variable_names ();
-
- /**
- * Return the value of the
- * function at the given
- * point. Unless there is only
- * one component (i.e. the
- * function is scalar), you
- * should state the component you
- * want to have evaluated; it
- * defaults to zero, i.e. the
- * first component.
- */
- virtual double value (const Point<dim> &p,
- const unsigned int component = 0) const;
-
- /**
- * Return all components of a
- * vector-valued function at the
- * given point @p p.
- *
- * <tt>values</tt> shall have the
- * right size beforehand,
- * i.e. #n_components.
- */
- virtual void vector_value (const Point<dim> &p,
- Vector<double> &values) const;
-
- /** @addtogroup Exceptions
- * @{ */
- DeclException2 (ExcParseError,
- int, char *,
- << "Parsing Error at Column " << arg1
- << ". The parser said: " << arg2);
-
- DeclException2 (ExcInvalidExpressionSize,
- int, int,
- << "The number of components (" << arg1
- << ") is not equal to the number of expressions ("
- << arg2 << ").");
-
- //@}
-private:
+ void initialize (const std::string &vars,
+ const std::string &expression,
+ const ConstMap &constants,
+ const bool time_dependent,
+ const bool use_degrees) DEAL_II_DEPRECATED;
+ /**
+ * Initialize the function. Same as above, but with <b>units</b>.
+ */
+
+ void initialize (const std::string &vars,
+ const std::string &expression,
+ const ConstMap &constants,
+ const ConstMap &units,
+ const bool time_dependent = false,
+ const bool use_degrees = false) DEAL_II_DEPRECATED;
+
+ /**
+ * A function that returns default names for variables, to be used in the
+ * first argument of the initialize() functions: it returns "x" in 1d,
+ * "x,y" in 2d, and "x,y,z" in 3d.
+ */
+ static
+ std::string
+ default_variable_names ();
+
+ /**
+ * Return the value of the function at the given point. Unless there is
+ * only one component (i.e. the function is scalar), you should state the
+ * component you want to have evaluated; it defaults to zero, i.e. the
+ * first component.
+ */
+ virtual double value (const Point<dim> &p,
+ const unsigned int component = 0) const;
+
+ /**
+ * Return all components of a vector-valued function at the given point @p
+ * p.
+ *
+ * <tt>values</tt> shall have the right size beforehand, i.e.
+ * #n_components.
+ */
+ virtual void vector_value (const Point<dim> &p,
+ Vector<double> &values) const;
+
+ /**
+ * @addtogroup Exceptions
+ * @{
+ */
+ DeclException2 (ExcParseError,
+ int, char *,
+ << "Parsing Error at Column " << arg1
+ << ". The parser said: " << arg2);
+
+ DeclException2 (ExcInvalidExpressionSize,
+ int, int,
+ << "The number of components (" << arg1
+ << ") is not equal to the number of expressions ("
+ << arg2 << ").");
+
+ //@}
+ private:
#ifdef DEAL_II_WITH_MUPARSER
/**
* place for the variables for each thread
mutable Threads::ThreadLocalStorage<std::vector<mu::Parser> > fp;
/**
- * keep track of all the constants, required to initialize fp in each thread
+ * keep track of all the constants, required to initialize fp in each
+ * thread
*/
std::map< std::string, double > constants;
/**
#endif
/**
- * State of usability. This
- * variable is checked every time
- * the function is called for
- * evaluation. It's set to true
- * in the initialize() methods.
- */
- bool initialized;
-
- /**
- * Number of variables. If this
- * is also a function of time,
- * then the number of variables
- * is dim+1, otherwise it is
- * dim. In the case that this is
- * a time dependent function, the
- * time is supposed to be the
- * last variable. If #n_vars is
- * not identical to the number of
- * the variables parsed by the
- * initialize() method, then an
- * exception is thrown.
- */
- unsigned int n_vars;
+ * State of usability. This variable is checked every time the function is
+ * called for evaluation. It's set to true in the initialize() methods.
+ */
+ bool initialized;
+
+ /**
+ * Number of variables. If this is also a function of time, then the
+ * number of variables is dim+1, otherwise it is dim. In the case that
+ * this is a time dependent function, the time is supposed to be the last
+ * variable. If #n_vars is not identical to the number of the variables
+ * parsed by the initialize() method, then an exception is thrown.
+ */
+ unsigned int n_vars;
};
FunctionParser<dim>::default_variable_names ()
{
switch (dim)
- {
- case 1:
- return "x";
- case 2:
- return "x,y";
- case 3:
- return "x,y,z";
- default:
- Assert (false, ExcNotImplemented());
- }
+ {
+ case 1:
+ return "x";
+ case 2:
+ return "x,y";
+ case 3:
+ return "x,y,z";
+ default:
+ Assert (false, ExcNotImplemented());
+ }
return "";
}
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