Class for mathematical functions. More...

Inheritance diagram for Function:

Public Member Functions
	Function (const Function &)
	Copy.

	Function (double d)
	Double to Function. More...

virtual	~Function ()
	Destructor.

virtual string	getName () const
	Returns the name. More...

Function &	setVerbose (bool verbose=true, ostream *log=&cout)
	Set function to be verbose. More...

virtual double	getValue () const
	Returns the value. More...

double	operator() (double x)
	Returns the value at a point. More...

double	operator() (double x, double y)
	Returns the value at a point. More...

void	setXInput (double)
	Set x input. More...

void	setYInput (double)
	Set y input. More...

double	getXInput ()
	Get x input. More...

double	getYInput ()
	Get y input. More...

virtual double	getLastValue () const
	Returns the value. More...

Function &	setPhysical (string s, Unit u)
	Returns the function graph. More...

virtual Function &	setXRange (double min, double max, double stepsize)
	Set the x range. More...

virtual Function &	setYRange (double min, double max, double stepsize)
	Set the y range. More...

string	getXInputName ()
	Get input name. More...

string	getYInputName ()
	Get input name. More...

Function &	setName (string s)
	Sets the name. More...

void	operator+= (Function &function)
	Add. More...

void	operator-= (Function &function)
	Subtract. More...

void	operator*= (Function &function)
	Multiply. More...

void	operator/= (Function &function)
	Divide. More...

Public Member Functions inherited from Physical
	Physical ()
	Construct.

	Physical (const Physical &)
	Copy.

	Physical (string name)
	Construct.

	Physical (string name, string unitPrefix, string unitSymbol)
	Construct.

	Physical (string name, Unit unit)
	Construct.

virtual string	getDescription ()
	Retrive the physical name. More...

virtual string	getPhysicalDescription ()
	Returns the physical description. More...

virtual string	getUnitName ()
	Returns the unit name.

virtual string	getUnitSymbol ()
	Returns the unit name.

virtual void	setDescription (string name)
	Set the name. More...

virtual void	setPhysicalDescription (string name)
	Set the name. Same as setDescription(). More...

virtual void	setUnit (Unit u)
	Set the unit.

virtual void	setUnitPrefix (int n)
	Set unit prefix. More...

virtual Unit	getUnit () const
	Retrieve the unit.

Protected Member Functions
	Function ()
	Default Constructor. More...

void	unvalidate ()
	Set unvalid. More...

Protected Attributes
int	nRefs
	we do reference counting

vector< Function * >	vParents
	parents, for ref counting

Friends
Function &	operator/ (Function &left, Function &right)
	Divide. More...

Function &	exp (Function &right)
	Exponential. More...

Function &	ln (Function &right)
	Logarithm. More...

Function &	sin (Function &right)
	Sine. More...

Function &	cos (Function &right)
	Cosine. More...

Function &	sqrt (Function &right)
	Square root. More...

Function &	square (Function &right)
	Square. More...

Function &	root (Function &left, Function &n)
	Root. More...

Function &	power (Function &left, Function &n)
	Power. More...

Function &	integral (Function &integrand, Function &integrator)
	Integral.. More...

Function &	increments (Function &right)
	Increments. More...

Function &	greater (Function &left, Function &right)
	Comparison. More...

Function &	smaller (Function &left, Function &right)
	Comparison. More...

Function &	operator> (Function &left, Function &right)
	Comparison. More...

Function &	operator< (Function &left, Function &right)
	Comparison. More...

Function &	operator<= (Function &left, Function &right)
	Comparison. More...

Function &	operator>= (Function &left, Function &right)
	Comparison. More...

Function &	sign (Function &right)
	Sign of a number.

ostream &	operator<< (ostream &os, Function &f)
	Appends the function specification string to a stream. More...

Function &	input (string)
	Create input. More...

Function &	cnst (double)
	Create a function from a constant.

Function &	cnst (double, string)
	Create a function from a constant and a name.

Function &	xtable (Matrix &, Function &right)
	Create a function from a matrix.

Function &	empty ()
	An empty function.

Detailed Description

Class for mathematical functions.

This class implements mathematical functions for use with the Display class (which supports only gnuplot output at the moment. Functions are created from Variables using +, -, *, /, exp, ln, sqrt, square, sqrt, power, or root. Note the special variables X and Y. Functions use referencing, and form an execution tree. When any variable in the function changes, the function output changes. Appending a function to a Display (using <<) will append the output with the current variable setting. That way you can append the same function to the same display, with different values of its variables, and the result will be different curves on top of each other. The function can be appended to any string using the << operator.

Constructor & Destructor Documentation

Function::Function ( )

inlineprotected

Default Constructor.

Constructs an empty function. This is mainly for use in the derived classes X and Y.

Function::Function ( double d )

Double to Function.

Constructs a constant from a double. Same as cnst(double).

Member Function Documentation

virtual double Function::getLastValue ( ) const

virtual

Returns the value.

Returns the last value of the function. This is the value which was produced by the last getValue() call. No recomputation is executed.

virtual string Function::getName ( ) const

virtual

Returns the name.

Returns: The name of the Function. This is the string which has been set with setName(), and which will appear as a gnuplot lable when this function is appended to a gnuplot display.

virtual double Function::getValue ( ) const

virtual

Returns the value.

Computes the current value of the function. This is dependent on variables and input.

double Function::getXInput ( )

Get x input.

This gets the x input of the whole tree. If input values are different at different branches, the first which is encountered will be returned.

string Function::getXInputName ( )

Get input name.

Returns the name of the first input, for instance 't' or 'x'.

double Function::getYInput ( )

Get y input.

This gets the y input of the whole tree. If input values are different at different branches, the first which is encountered will be returned.

string Function::getYInputName ( )

Get input name.

Returns the name of the second input, for instance 't' or 'x'.

double Function::operator() ( double x )

inline

Returns the value at a point.

Computes the current value of the function. This is dependent on variables and input.

double Function::operator()	(	double	x,
		double	y
	)

inline

Returns the value at a point.

Computes the current value of the function. This is dependent on variables and input.

void Function::operator*= ( Function & function )

Multiply.

Multiplies the given function to this function object.

void Function::operator+= ( Function & function )

Add.

Adds the given function to this function object.

void Function::operator-= ( Function & function )

Subtract.

Subtracts the given function from the object..

void Function::operator/= ( Function & function )

Divide.

Divides the given function to this function object.

Function& Function::setName ( string s )

Sets the name.

This function returns a reference to its object for convenience.

Function& Function::setPhysical	(	string	s,
		Unit	u
	)

Returns the function graph.

Returns the function graph. This is dependent on variables and input range. Sets the physical type. This sets a physical name (like 'voltage'), and a unit (like mV).

Function& Function::setVerbose	(	bool	verbose = `true`,
		ostream *	log = `&cout`
	)

Set function to be verbose.

If this is set, the function will append its current value and its name to a stream, each time getValue() is called. setVerbose() will set all subfunctions to be verbose as well. This way a log of the whole calculation will be appended to a stream.

Parameters

verbose	whether the function is verbose (sends state log-messages to a stream)
log	the stream receiving the log messages

void Function::setXInput ( double )

Set x input.

This sets the x input of the whole tree to the given value.

virtual Function& Function::setXRange	(	double	min,
		double	max,
		double	stepsize
	)

virtual

Set the x range.

Sets the x range of the function, i.e. the function will be plotted in a range from minimum to maximum, with the given step size.

Parameters

min	minimum
max	maximum
stepsize	step size

void Function::setYInput ( double )

Set y input.

This sets the y input of the whole tree to the given value.

virtual Function& Function::setYRange	(	double	min,
		double	max,
		double	stepsize
	)

virtual

Set the y range.

Sets the y range of the function, i.e. the function will be plotted in a range from minimum to maximum, with the given step size.

Parameters

min	minimum
max	maximum
stepsize	step size

void Function::unvalidate ( )

protected

Set unvalid.

After this, the function will perform a full computation, if getValue() is called. Otherwise just the last value is return. This function needs to be called if some input has changed lower down in the execution tree.

Friends And Related Function Documentation

Function& cos ( Function & right )

friend

Cosine.

Creates a Function which is the logarithm of the input function.

Function& exp ( Function & right )

friend

Exponential.

Creates a Function which is the exponential of the input function.

Function& greater	(	Function &	left,
		Function &	right
	)

friend

Comparison.

Returns 1.0 at places where the comparison is true, and 0.0 at places where the comparison is false.

Function& increments ( Function & right )

friend

Increments.

Creates the differential df(x) of a given integrand f(x). If plotted, you will see the function

$\mbox{Function(t)} = d f(x)$

.

Function& input ( string )

friend

Create input.

Creates a function which serves as input for other functions.

Function& integral	(	Function &	integrand,
		Function &	integrator
	)

friend

Integral..

Creates the undefinite integral of the given integrand. If plotted, you will see the function

$\mbox{Function(t)} = \int_0^t f(x) dx$

.

Function& ln ( Function & right )

friend

Logarithm.

Creates a Function which is the logarithm of the input function.

Function& operator/	(	Function &	left,
		Function &	right
	)

friend

Divide.

Creates a Function which is the quotient of the two input functions.

Function& operator<	(	Function &	left,
		Function &	right
	)

friend

Comparison.

Returns 1.0 at places where the comparison is true, and 0.0 at places where the comparison is false.

ostream& operator<<	(	ostream &	os,
		Function &	f
	)

friend

Appends the function specification string to a stream.

The appended string is gnuplot readable, and may contain lots of parentheses, depending on the complexity of the function.

Function& operator<=	(	Function &	left,
		Function &	right
	)

friend

Comparison.

Returns 1.0 at places where the comparison is true, and 0.0 at places where the comparison is false.

Function& operator>	(	Function &	left,
		Function &	right
	)

friend

Comparison.

Returns 1.0 at places where the comparison is true, and 0.0 at places where the comparison is false.

Function& operator>=	(	Function &	left,
		Function &	right
	)

friend

Comparison.

Returns 1.0 at places where the comparison is true, and 0.0 at places where the comparison is false.

Function& power	(	Function &	left,
		Function &	n
	)

friend

Power.

Returns: A Function which is the nth power of the input.

Function& root	(	Function &	left,
		Function &	n
	)

friend

Root.

Returns: A Function which is the nth root of the input..

Function& sin ( Function & right )

friend

Sine.

Creates a Function which is the logarithm of the input function.

Function& smaller	(	Function &	left,
		Function &	right
	)

friend

Comparison.

Returns 1.0 at places where the comparison is true, and 0.0 at places where the comparison is false.

Function& sqrt ( Function & right )

friend

Square root.

Creates a Function which is the sqare root of the input function.

Function& square ( Function & right )

friend

Square.

Creates a Function which is the sqare of the input function.

Public Member Functions

Protected Member Functions

Protected Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation