Package net.sf.tweety.math.func.fuzzy

Class TNorm

java.lang.Object

net.sf.tweety.math.func.fuzzy.TNorm

All Implemented Interfaces:

BinaryFunction<Double,Double,Double>

Direct Known Subclasses:

LukasiewiczNorm, MinimumNorm, ProductNorm

public abstract class TNorm
extends Object
implements BinaryFunction<Double,Double,Double>

Represents a T-norm in fuzzy logic, i.e., a generalization of a logical conjunction on values in [0,1].

Author:

Matthias Thimm

Constructor Summary

Constructors

Constructor	Description
TNorm()

Method Summary

Modifier and Type	Method	Description
abstract Double	eval(Double val1, Double val2)	Evaluates the function for the given elements.
Double	eval(Collection<Double> vals)	Generalizes this norm on sets of input parameters (as t-norms are associative, the order is not important).
Term	evalTerm(Collection<Term> vals)	Gives a representation of this norm as a mathematical term.
abstract Term	evalTerm(Term val1, Term val2)	Gives a representation of this norm as a mathematical term
abstract TCoNorm	getDualCoNorm()	Returns the dual T-conorm of this T-norm.
abstract boolean	isNilpotent()	A T-norm is nilpotent if there are x,y>0 with t(x,y)=0

Methods inherited from class java.lang.Object

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

Constructor Detail

TNorm

public TNorm()

Method Detail

eval

public abstract Double eval(Double val1,
                            Double val2)

Description copied from interface: BinaryFunction

Evaluates the function for the given elements.

Specified by:

eval in interface BinaryFunction<Double,Double,Double>

Parameters:

val1 - some element

val2 - some element

Returns:

the value of the element.

eval

public Double eval(Collection<Double> vals)

Generalizes this norm on sets of input parameters (as t-norms are associative, the order is not important).

Parameters:

vals - a set of values

Returns:

the evaluation result on the input

evalTerm

public abstract Term evalTerm(Term val1,
                              Term val2)

Gives a representation of this norm as a mathematical term

Parameters:

val1 - the term denoting the first parameter

val2 - the term denoting the second parameter

Returns:

the term denoting this norm evaluation on the two terms

evalTerm

public Term evalTerm(Collection<Term> vals)

Gives a representation of this norm as a mathematical term. Generalizes this norm on sets of input parameters (as t-norms are associative, the order is not important).

Parameters:

vals - a set of value terms

Returns:

the evaluation result on the input as a term

getDualCoNorm

public abstract TCoNorm getDualCoNorm()

Returns the dual T-conorm of this T-norm.

Returns:

the dual T-conorm of this T-norm.

isNilpotent

public abstract boolean isNilpotent()

A T-norm is nilpotent if there are x,y>0 with t(x,y)=0

Returns:

true if the norm is nilpotent