ilog.cp

Class IloCP.DoubleParam

java.lang.Object

ilog.cp.IloCP.DoubleParam

Enclosing class:

IloCP

public abstract static class IloCP.DoubleParam
extends java.lang.Object

Symbolic parameter names for double-valued IloCP parameters.

Field Summary

Fields

Modifier and Type	Field and Description
static IloCP.DoubleParam	ConflictRefinerTimeLimit This parameter limits the CPU time spent before terminating the conflict refiner.
static IloCP.DoubleParam	DynamicProbingStrength This parameter controls the effort which is dedicated to dynamic probing.
static IloCP.DoubleParam	FailureDirectedSearchEmphasis This parameter controls how much time CP Optimizer invests into failure-directed search once it is started.
static IloCP.DoubleParam	OptimalityTolerance Double control parameter.
static IloCP.DoubleParam	RelativeOptimalityTolerance This parameter sets a relative tolerance on the objective value for optimization models.
static IloCP.DoubleParam	RestartGrowthFactor When IloCP.IntParam.SearchType is set to IloCP.ParameterValues.Restart, a depth-first search is restarted after a certain number of failures.
static IloCP.DoubleParam	TimeLimit This parameter limits the CPU time spent solving before terminating a search.

Constructor Summary

Constructors

Constructor and Description
IloCP.DoubleParam()

Method Summary

Methods

Modifier and Type	Method and Description
abstract int	getValue()

Methods inherited from class java.lang.Object

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

Field Detail

OptimalityTolerance

public static final IloCP.DoubleParam OptimalityTolerance

Double control parameter. This parameter sets an absolute tolerance on the objective value for optimization models. This means that when CP Optimizer reports an optimal solution found, then there is no solution which improves the objective by more than the value of this parameter. The default value of this parameter is 0. This parameter is used in conjunction with IloCP.NumParam.RelativeOptimalityTolerance. The optimality of a solution is proven if either of the two parameters' criteria is fulfilled.

RelativeOptimalityTolerance

public static final IloCP.DoubleParam RelativeOptimalityTolerance

This parameter sets a relative tolerance on the objective value for optimization models. This means that when CP Optimizer reports an optimal solution found, then there is no solution which improves the objective by more than the absolute value of the objective times the value of this parameter. The default value of this parameter is 1e-4. This parameter is used in conjunction with IloCP.DoubleParam.OptimalityTolerance. The optimality of a solution is proven if either of the two parameters' criteria are fulfilled.

TimeLimit

public static final IloCP.DoubleParam TimeLimit

This parameter limits the CPU time spent solving before terminating a search. The time is given in seconds. The possible values of this parameter range from 0 to IloCP.Infinity. A value of the largest double does not set any limit. The value IloCP.Infinity is the default value.

RestartGrowthFactor

public static final IloCP.DoubleParam RestartGrowthFactor

When IloCP.IntParam.SearchType is set to IloCP.ParameterValues.Restart, a depth-first search is restarted after a certain number of failures. This parameter controls the increase of this number between restarts. If the last fail limit was f after a restart, for next run, the new fail limit will be f times the value of this parameter. Possible values of this parameter range from 1.0 to IloCP.Infinity. The default value is 1.15. The initial fail limit can be controlled with the parameter IloCP.IntParam.RestartFailLimit.

DynamicProbingStrength

public static final IloCP.DoubleParam DynamicProbingStrength

This parameter controls the effort which is dedicated to dynamic probing. It determines the ratio P/R where P is the effort dedicated to dynamic probing, and R is the rest of the search effort. Changing this parameter has no effect unless the IloCP.IntParam.DynamicProbing parameter is set to IloCP.ParameterValues.Auto or IloCP.ParameterValues.On. When IloCP.IntParam.DynamicProbing has value IloCP.ParameterValues.On, the probing strength is held constant throughout the search process. When IloCP.IntParam.DynamicProbing has value IloCP.ParameterValues.Auto, the probing strength starts off at the specified value and is thereafter adjusted automatically. Possible values for this parameter range from 0.001 to 1000. A value of 1.0 indicates that dynamic probing will consume a roughly equal amount of effort as the rest of the search. The default value of this parameter is 0.03, meaning that around 3% of total search time is dedicated to dynamic probing.

ConflictRefinerTimeLimit

public static final IloCP.DoubleParam ConflictRefinerTimeLimit

This parameter limits the CPU time spent before terminating the conflict refiner. The possible values of this parameter range from 0 to IloInfinity. A value of IloInfinity does not set any limit. The value IloInfinity is the default value.

FailureDirectedSearchEmphasis

public static final IloCP.DoubleParam FailureDirectedSearchEmphasis

This parameter controls how much time CP Optimizer invests into failure-directed search once it is started. The default value IloCP.ParameterValues.Auto means that CP Optimizer observes the performance of failure-directed search and decides automatically how much time is invested. Any other value between means that once failure-directed search has started, it is used by the given number of workers. The value does not have to be integer. For example, a value of 1.5 means that the first worker spends 100% of its time on failure-directed search, the second worker spends 50% of its time on failure-directed search, and the remainder spend none of their time.

Constructor Detail

IloCP.DoubleParam

public IloCP.DoubleParam()

Method Detail

getValue

public abstract int getValue()