genius.core.utility

Class AbstractUtilitySpace

java.lang.Object

genius.core.utility.AbstractUtilitySpace

All Implemented Interfaces:

UtilitySpace, java.io.Serializable

Direct Known Subclasses:

AdditiveUtilitySpace, ConstraintUtilitySpace, FlattenedUtilitySpace, NonlinearUtilitySpace, UncertainUtilitySpace

public abstract class AbstractUtilitySpace
extends java.lang.Object
implements UtilitySpace

Implements the basic functionality of UtilitySpace but does not implement the details. Adds the discountFactor as a mechanism to implement discount. A filename is remembered. Also adds default functionality to support implementation of concrete utility spaces. In the future this class may have to be split in more parts.

Author:

W.Pasman 5nov15 (refactor from old code).

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	DISCOUNT_FACTOR
protected java.lang.String	fileName
static java.lang.String	RESERVATION

Constructor Summary

Constructors

Constructor and Description
AbstractUtilitySpace(Domain dom) sets domain and tries to load the file into XML root.

Method Summary

Modifier and Type	Method and Description
void	checkReadyForNegotiation(Domain dom) Check if this utility space is ready for negotiation.
java.lang.Double	discount(double util, double time) Specific implementation for discount, based on a discount factor.
double	getDiscountFactor()
Domain	getDomain()
java.lang.String	getFileName()
Bid	getMaxUtilityBid() Returns the maximum bid in the utility space.
Bid	getMinUtilityBid() Returns the worst bid in the utility space.
java.lang.String	getName()
java.lang.Double	getReservationValue() The reservation value is the least favourable point at which one will accept a negotiated agreement.
double	getReservationValueUndiscounted() Equivalent to getReservationValue(), but always returns a double value.
double	getReservationValueWithDiscount(double time) The discounted version of getReservationValue().
double	getReservationValueWithDiscount(TimeLineInfo timeline) The discounted version of getReservationValue().
double	getUtilityWithDiscount(Bid bid, double time) See getUtilityWithDiscount(Bid, double).
double	getUtilityWithDiscount(Bid bid, TimeLineInfo timeline) Let d in (0, 1) be the discount factor.
boolean	isDiscounted()
void	setDiscount(double newDiscount)
void	setReservationValue(double newRV)
protected double	validateDiscount(double df)

Methods inherited from class java.lang.Object

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

Methods inherited from interface genius.core.utility.UtilitySpace

copy, getUtility, isComplete, toXML

Field Detail

DISCOUNT_FACTOR

public static final java.lang.String DISCOUNT_FACTOR

See Also:

Constant Field Values

RESERVATION

public static final java.lang.String RESERVATION

See Also:

Constant Field Values

fileName

protected java.lang.String fileName

Constructor Detail

AbstractUtilitySpace

public AbstractUtilitySpace(Domain dom)

sets domain and tries to load the file into XML root.

Parameters:

dom - the Domain to load

Method Detail

getDomain

public Domain getDomain()

Specified by:

getDomain in interface UtilitySpace

Returns:

domain belonging to this preference profile.

setReservationValue

public void setReservationValue(double newRV)

Parameters:

newRV - new reservation value.

setDiscount

public void setDiscount(double newDiscount)

Parameters:

newDiscount - new discount factor.

getReservationValue

public java.lang.Double getReservationValue()

The reservation value is the least favourable point at which one will accept a negotiated agreement. Also sometimes referred to as the walk away point.

This is value remains constant during the negotiation. However, by default, the reservation value descreases with time. To obtain the discounted version of the reservation value, use getReservationValueWithDiscount(TimeLineInfo).

Specified by:

getReservationValue in interface UtilitySpace

Returns:

undiscounted reservation value of the preference profile (may be null).

getReservationValueUndiscounted

public double getReservationValueUndiscounted()

Equivalent to getReservationValue(), but always returns a double value. When the original reservation value is null it returns the default value 0.

Returns:

undiscounted reservation value of the preference profile (never null).

See Also:

getReservationValue()

getReservationValueWithDiscount

public double getReservationValueWithDiscount(double time)

The discounted version of getReservationValue().

Parameters:

time - at which we want to know the utility of the reservation value.

Returns:

discounted reservation value.

getReservationValueWithDiscount

public double getReservationValueWithDiscount(TimeLineInfo timeline)

The discounted version of getReservationValue().

Parameters:

timeline - specifying the current time in the negotiation.

Returns:

discounted reservation value.

isDiscounted

public boolean isDiscounted()

Returns:

true if the domain features discounts.

getDiscountFactor

public final double getDiscountFactor()

Returns:

Discount factor of this preference profile.

getFileName

public java.lang.String getFileName()

Returns:

filename of this preference profile.

getUtilityWithDiscount

public double getUtilityWithDiscount(Bid bid,
                                     TimeLineInfo timeline)

Let d in (0, 1) be the discount factor. (If d ≤ 0 or d ≥ 1, we assume that d = 1.) Let t in [0, 1] be the current time, as defined by the Timeline. We compute the discounted utility discountedUtility as follows: discountedUtility = originalUtility * d^t. For t = 0 the utility remains unchanged, and for t = 1 the original utility is multiplied by the discount factor. The effect is almost linear in between. Works with any utility space.

Parameters:

bid - of which we are interested in its utility.

timeline - indicating the time passed in the negotiation.

Returns:

discounted utility.

getUtilityWithDiscount

public double getUtilityWithDiscount(Bid bid,
                                     double time)

See getUtilityWithDiscount(Bid, double).

Parameters:

bid - of which we want to know the utility at the given time.

time - at which we want to know the utility of the bid.

Returns:

discounted utility.

discount

public java.lang.Double discount(double util,
                                 double time)

Specific implementation for discount, based on a discount factor. Computes: discountedUtil = util * Math.pow(discount, time). Checks for bounds on the discount factor and time.

Specified by:

discount in interface UtilitySpace

Parameters:

util - the undiscounted utility as coming from UtilitySpace.getUtility(Bid).

time - a real number in the range [0,1] where 0 is the start of the negotiation and 1 the end. See also TimeLineInfo.

Returns:

the time-discounted utility at given time.

validateDiscount

protected double validateDiscount(double df)

getMaxUtilityBid

public final Bid getMaxUtilityBid()
                           throws java.lang.Exception

Returns the maximum bid in the utility space. This is only supported for linear utility spaces. Totally revised, brute-force search now.

Returns:

a bid with the maximum utility value attainable in this util space

Throws:

java.lang.Exception - if there is no bid at all in this util space.

getMinUtilityBid

public Bid getMinUtilityBid()
                     throws java.lang.Exception

Returns the worst bid in the utility space. This is only supported for linear utility spaces.

Returns:

a bid with the lowest possible utility

Throws:

java.lang.Exception - if there is no bid at all in the util space

checkReadyForNegotiation

public void checkReadyForNegotiation(Domain dom)
                              throws java.lang.Exception

Check if this utility space is ready for negotiation. To be so, the domain must match the given domain and the space must be complete.

Parameters:

dom - is the domain in which nego is taking place

Throws:

java.lang.Exception - if utility space is incomplete (@see isComplete())

getName

public java.lang.String getName()

Specified by:

getName in interface UtilitySpace

Returns:

a simple name for easy reference. Typically the filename.