Package gov.nasa.jpl.aerie.scheduler.solver.stn

Class STN

java.lang.Object

gov.nasa.jpl.aerie.scheduler.solver.stn.STN

public class STN
extends Object

Representation of a simple temporal network (Dechter, Meiri, and Pearl, 1991). Set of timepoint variables with linear constraints between them Classical constraint programming setting where - Each variable has a domain - We want to propagate the constraints to find a solution to the problem or ensure there is not one To solve the constraints, we use bellman-ford algorithm. if a negative cycle is detected during propagation, the network is infeasible otherwise, the new variable domains are updated and can be queried. Domains here represent the flexibility associated with each timepoint.

Constructor Summary

Constructors

Constructor	Description
STN()

Method Summary

Modifier and Type	Method	Description
void	addBeforeCst(String tp1, String tp2)	tp1 is before tp2 equivalent to the constraint tp1 --- [0, +inf] ---> tp2 Maps to two edges in a distance graph i --- +inf ---> j i <--- -0 --- j we can remove the first one and keep only the second one
void	addDurCst(String tp1, String tp2, double min, double max)
void	addTimepoint(String tp)
double	getDist(String a, String b)	gets the weight on link a-->b
org.apache.commons.lang3.tuple.Pair<Double,Double>	getDurCst(String a, String b)
void	removeTimepoint(String tp1)
String	toDOT()
boolean	update()

Methods inherited from class java.lang.Object

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

Constructor Details

STN

public STN()

Method Details

toDOT

public String toDOT()

addBeforeCst

public void addBeforeCst(String tp1,
 String tp2)

tp1 is before tp2 equivalent to the constraint tp1 --- [0, +inf] ---> tp2 Maps to two edges in a distance graph i --- +inf ---> j i <--- -0 --- j we can remove the first one and keep only the second one

removeTimepoint

public void removeTimepoint(String tp1)

addDurCst

public void addDurCst(String tp1,
 String tp2,
 double min,
 double max)

getDurCst

public org.apache.commons.lang3.tuple.Pair<Double,Double> getDurCst(String a,
 String b)

addTimepoint

public void addTimepoint(String tp)

update

public boolean update()

getDist

public double getDist(String a,
 String b)

gets the weight on link a-->b