rafa.math.gen
Class Function

java.lang.Object
  rafa.math.gen.Function

All Implemented Interfaces:

java.beans.PropertyChangeListener, java.util.EventListener, Dependent

public class Function
extends java.lang.Object
implements Dependent, java.beans.PropertyChangeListener

Wrapper around a MESP parser, which simplifies the task of retrieving automatically non-default functions from named generators in the NameRegistry.

Author:

rafa

Field Summary

protected static java.lang.String[]	DEFAULTS The default function names as provided by MESP's FuncMap.loadDefaultFunctions().
protected static java.lang.String	X The independent variable

Constructor Summary

Function(java.lang.String function)

Function(java.lang.String function, java.util.Map<java.lang.String,java.lang.Number> vars, java.util.Map<java.lang.String,java.util.List<? extends java.lang.Number>> funcs)

Method Summary

protected void	checkName(java.lang.String name) Checks that a function name is valid for the parser.
java.util.Collection<Dependency>	getDependencies(java.lang.Object target) Gets detailed information about the dependencies of this object on a given one.
protected java.util.List<java.lang.String>	getFunctionNames() Retrieves the names of the functions (helpers) actually used by this one, i.e.
double	getValue(double xValue, boolean refreshFunctions) Gets the function value for a given value of x.
protected void	loadFuncMap() Loads every known function - predefined by MESP and user-defined (in the name registry) - for later use.
protected void	loadFuncMap(java.util.Map<java.lang.String,java.util.List<? extends java.lang.Number>> funcs) Loads functions which may be used as helpers.
void	loadFunction(java.lang.String n) Loads one helper function from the name registry into the function map.
void	loadFunction(java.lang.String f, java.util.List<? extends java.lang.Number> list) Loads a list of numbers to be used as a helper function by this one.
void	loadVariable(java.lang.String name, java.lang.Number value) Loads a variable to be used from this function.
protected void	loadVarMap(java.util.Map<java.lang.String,java.lang.Number> vars)
protected void	parse(java.lang.String function) Updates the function expression.
protected void	parse(java.lang.String function, java.util.Map<java.lang.String,java.lang.Number> vars, java.util.Map<java.lang.String,java.util.List<? extends java.lang.Number>> funcs)
void	propertyChange(java.beans.PropertyChangeEvent e)
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

X

protected static final java.lang.String X

The independent variable

See Also:

Constant Field Values

DEFAULTS

protected static final java.lang.String[] DEFAULTS

The default function names as provided by MESP's FuncMap.loadDefaultFunctions().

Constructor Detail

Function

public Function(java.lang.String function)

Function

public Function(java.lang.String function,
                java.util.Map<java.lang.String,java.lang.Number> vars,
                java.util.Map<java.lang.String,java.util.List<? extends java.lang.Number>> funcs)

Method Detail

loadVarMap

protected void loadVarMap(java.util.Map<java.lang.String,java.lang.Number> vars)

loadFuncMap

protected void loadFuncMap()

Loads every known function - predefined by MESP and user-defined (in the name registry) - for later use.

loadFuncMap

protected void loadFuncMap(java.util.Map<java.lang.String,java.util.List<? extends java.lang.Number>> funcs)

Loads functions which may be used as helpers. These are taken from MESP (predefined), the name registry (user-defined, global scope) and the passed parameter (user-defined, local scope).

Parameters:

funcs - the functions to be used locally in this one (not shared with any others).

loadFunction

public void loadFunction(java.lang.String n)

Loads one helper function from the name registry into the function map.

Parameters:

n - The name of the function (generator) as stored in the name registry.

loadFunction

public void loadFunction(java.lang.String f,
                         java.util.List<? extends java.lang.Number> list)

Loads a list of numbers to be used as a helper function by this one. Example: if the list [ 11, 22, 33, 44 ] is passed with the name foo, the string foo(0) will evaluate to 11 and foo(3) to 33.

Parameters:

f - the name given to the function.

list - A list of numbers. If null, the NameRegistry is searched for the name to get a number generator.

loadVariable

public void loadVariable(java.lang.String name,
                         java.lang.Number value)

Loads a variable to be used from this function. If already existing, it is overwritten.

Parameters:

name - the variable name.

value - the variable value.

getValue

public double getValue(double xValue,
                       boolean refreshFunctions)

Gets the function value for a given value of x.

Parameters:

xValue - the value assigned to the x variable in the expression.

refreshFunctions - should the function map be refreshed?

Returns:

the value of the function.

parse

protected void parse(java.lang.String function)

Updates the function expression.

Parameters:

function -

parse

protected void parse(java.lang.String function,
                     java.util.Map<java.lang.String,java.lang.Number> vars,
                     java.util.Map<java.lang.String,java.util.List<? extends java.lang.Number>> funcs)

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getFunctionNames

protected java.util.List<java.lang.String> getFunctionNames()

Retrieves the names of the functions (helpers) actually used by this one, i.e. those which appear in the function expression.

Returns:

A list of function names.

checkName

protected void checkName(java.lang.String name)
                  throws InvalidNameException

Checks that a function name is valid for the parser. Note that it does not check for existing generator names - which is already done by NameRegistry, but only for existing predefined default functions (see DEFAULTS).

Parameters:

name - a function name

Throws:

ExistingNameException - if the name collides with a predefined function name.

InvalidNameException - if the name is not valid.

getDependencies

public java.util.Collection<Dependency> getDependencies(java.lang.Object target)

Description copied from interface: Dependent

Gets detailed information about the dependencies of this object on a given one.

Specified by:

getDependencies in interface Dependent

Parameters:

target - the required object. If null, all of the dependencies will be returned.

Returns:

a collection of Dependency objects pointing to the same object (target), or null if there is no dependency on that object.

propertyChange

public void propertyChange(java.beans.PropertyChangeEvent e)

Specified by:

propertyChange in interface java.beans.PropertyChangeListener