stella.merit

Class TerminalMerit

java.lang.Object

util.PropertyContainer

stella.merit.AbstractMerit

stella.merit.TerminalMerit

All Implemented Interfaces:

Serializable, Cloneable, EndpointDefining, Meriting, PropertySupplying

public class TerminalMerit
extends AbstractMerit
implements EndpointDefining

A merit calculating its timeslot as being constant until a certain time in the future, then rather appruptely falling to zero. The steepness of the decrease can be tuned with the KEY_WIDTH (σ) parameter, while the terminal point, at which the timeslot has fallen to half of its value, is defined with KEY_T0 (t0). The overall weight of the merit, i.e. its scaling between zero and one, is defined in KEY_WEIGHT (k). The drop is modeled on top of a tanh function. The default value of KEY_TANHSTRETCH (s) is almost always sufficient. Different time paramters can be used, the default is julian date. The formula used in the region stretching from t0-σ to t0+σ reads as follows

 ts(t) = k·½(1-tanh(s·(t-t0)/σ))
 

Outside this region, the merit is k or zero. This merit is EndpointDefining.

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Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
private static double	DEFTANHSTRETCH The default stretch factor in the tanh-transition region.
private static String	DEFTIME Default remaining night-time parameter name.
private static double	DEFWEIGHT Default value for the weight.
private static double	DEFWIDTH Default half-width of the transition region.
static String	KEY_T0 The terminal time, in the middle of the drop-to-zero intervall.
static String	KEY_TANHSTRETCH The key linked to the stretch of the tanh in the drop phase.
static String	KEY_TIME The name of the time parameter used.
static String	KEY_WEIGHT The key linked to the weight of the terminal merit.
static String	KEY_WIDTH Half of the time it takes the merit to drop to zero.

Fields inherited from class util.PropertyContainer

KEY_LISTSEPARATOR, KEY_MAPKEYVALUECHAR, KEY_MAPSEPARATOR

Fields inherited from interface util.PropertySupplying

CONFIG, KEY_CLASS

Constructor Summary

Constructors

Constructor and Description
TerminalMerit(Map prop) Constructs a new window merit using only default weights and impacts.

Method Summary

Modifier and Type	Method and Description
double	getMerit(GlobalGrouping set, Appointable target, Collection ignore, long dummy) Calculates the terminal merit.
boolean	isCompleted(GlobalGrouping set, Appointable target) Test, if this target is completed.

Methods inherited from class stella.merit.AbstractMerit

createMerit, getInitializer, initMerit

Methods inherited from class util.PropertyContainer

augment, augment, augment, augment, augment, clone, defaultBoolean, defaultChar, defaultDouble, defaultFloat, defaultInt, defaultLong, defaultObject, defaultObject, defaultProperties, defaultProperty, getAsBoolean, getAsChar, getAsDouble, getAsEnums, getAsFloat, getAsInt, getAsList, getAsLong, getAsMap, getAsMap, getAsObject, getAsObject, getProperties, getProperty, has, initProperties, isNew, parseObject, parseObject, reload, reload, removeProperty, requires, rescanned, setObject, setProperties, setProperty, stringProperties, toString

Methods inherited from class java.lang.Object

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

Field Detail

KEY_WEIGHT

public static final String KEY_WEIGHT

The key linked to the weight of the terminal merit.

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Constant Field Values

KEY_WIDTH

public static final String KEY_WIDTH

Half of the time it takes the merit to drop to zero.

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Constant Field Values

KEY_T0

public static final String KEY_T0

The terminal time, in the middle of the drop-to-zero intervall.

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Constant Field Values

KEY_TANHSTRETCH

public static final String KEY_TANHSTRETCH

The key linked to the stretch of the tanh in the drop phase.

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Constant Field Values

KEY_TIME

public static final String KEY_TIME

The name of the time parameter used.

See Also:

Constant Field Values

DEFWEIGHT

private static final double DEFWEIGHT

Default value for the weight.

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Constant Field Values

DEFWIDTH

private static final double DEFWIDTH

Default half-width of the transition region.

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Constant Field Values

DEFTANHSTRETCH

private static final double DEFTANHSTRETCH

The default stretch factor in the tanh-transition region.

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Constant Field Values

DEFTIME

private static final String DEFTIME

Default remaining night-time parameter name.

See Also:

Constant Field Values

Constructor Detail

TerminalMerit

public TerminalMerit(Map prop)

Constructs a new window merit using only default weights and impacts. The proper way to create a window merit is using the AbstractMerit.createMerit(java.util.Map<java.lang.String, java.lang.String>) method. This create method also takes care of proper parameter overloading.

Method Detail

getMerit

public double getMerit(GlobalGrouping set,
                       Appointable target,
                       Collection ignore,
                       long dummy)

Calculates the terminal merit. After a certain time, the target will never be picked again, thus returning zero. This merit focuses on the starting time of the target, thus the time span is ignored.

Specified by:

getMerit in interface Meriting

Parameters:

set - Current observing conditions.

target - The actual target.

ignore - All targets, observable or not.

dummy - The relevant time span in ms.

isCompleted

public boolean isCompleted(GlobalGrouping set,
                           Appointable target)

Test, if this target is completed. In terms of a terminal merit, this means checking if the current time is after the terminal time. In the latter case, i.e. when the actual merit is zero, true is returned.

Specified by:

isCompleted in interface EndpointDefining