Class IloSchedulerEnv

The class IloSchedulerEnv is the repository of all the default parameters used when creating new modeling objects. There can be at most one IloSchedulerEnv defined on a given instance of IloEnv.

Avoiding Overflows

In order to avoid overflows in computations by Scheduler Engine, an efficient policy is to limit the domain of all extracted integer variables to an interval of [-L,L]. For example, a variable whose lower bound is 0 and upper bound is IloInfinity will be extracted as a variable with the domain [0,L]. This limit L is set by the member function IloSchedulerEnv::setIntMaxAtExtraction. At extraction, this limit is used only for variables that are used by Scheduler objects or constraints, as the start and end times, the capacity variables or the precedence delays. Please note that there is an exception for the cost sum variable (class IloTransitionCost). For this variable, the limit L is not applied because there is usually no overflow with this variable. The default value of this limit is IloIntMax/2, which avoids overflows in most cases.

For more information, see IloNumToNumStepFunction, IloNumToAnySetStepFunction, and IloIntervalList in the extensions section of the IBM ILOG Concert Technology Reference Manual, Parameter Classes.

This constructor creates a new instance of IloSchedulerEnv if none currently exists on the given instance of IloEnv. If a scheduler environment has already been created on the environment, then the new handle uses it, and points to the same implementation. When created, an instance of IloSchedulerEnv will create all the default parameters and initialize them to their default values.

This constructor creates an instance of the handle class IloSchedulerEnv from the pointer to an instance of the implementation class IloSchedulerEnvI.

This member function returns the default instance of the activity basic parameter. Modeling objects that are created will point to this instance, which can thus be shared between several objects.

This member function returns the default instance of the activity break parameter. Modeling objects that are created will point to this instance, which can thus be shared between several objects.

This member function returns the default instance of the activity constraints parameter. Modeling objects that are created will point to this instance, which can thus be shared between several objects.

This member function returns the default instance of the activity overlap parameter. Modeling objects that are created will point to this instance, which can thus be shared between several objects.

This member function returns the default instance of the activity shift parameter. Modeling objects that are created will point to this instance, which can thus be shared between several objects.

This member function returns the default instance of the break list parameter. Modeling objects that are created will point to this instance, which can thus be shared between several objects.

This member function returns the default instance of the capacity enforcement intervals parameter. Modeling objects that are created will point to this instance, which can thus be shared between several objects.

This member function returns the default instance of the maximal capacity parameter. Modeling objects that are created will point to this instance, which can thus be shared between several objects.

This member function returns the default instance of the minimal capacity parameter. Modeling objects that are created will point to this instance, which can thus be shared between several objects.

This member function returns the instance of IloEnv on which the called object was built.

This member function returns the time horizon. The time origin and the time horizon are used by default at extraction to initialize the time window over which resource capacity constraints must be enforced. The origin and horizon are also used for setting earliest start times and latest end times of activities when they are created.

This member function returns a pointer to the implementation object corresponding to the invoking activity (a handle).

This member function returns the default instance of the initial occupation parameter. Modeling objects that are created will point to this instance, which can thus be shared between several objects.

This member function returns the value of the maximum limit of the domain of the integer variables used by Scheduler Engine.

Avoiding Overflows

In order to avoid overflows in computations by Scheduler Engine, an efficient policy is to limit the domain of all extracted integer variables to an interval of [-L,L]. For example, a variable whose lower bound is 0 and upper bound is IloInfinity will be extracted as a variable with the domain [0,L]. This limit L is set by the member function IloSchedulerEnv::setIntMaxAtExtraction. At extraction, this limit is used only for variables that are used by Scheduler objects or constraints, as the start and end times, the capacity variables or the precedence delays. Please note that there is an exception for the cost sum variable (class IloTransitionCost). For this variable, the limit L is not applied because there is usually no overflow with this variable. The default value of this limit is IloIntMax/2, which avoids overflows in most cases.

For more information, see Parameters Organized by Function and IloNumToNumStepFunction in the IBM ILOG Concert Technology Reference Manual.

The member function returns the default instance of the texture parameter on maximum capacity constraints. Modeling objects that are created will point to this instance, which can thus be shared between several objects.

The member function returns the default instance of the texture parameter on minimum capacity constraints. Modeling objects that are created will point to this instance, which can thus be shared between several objects.

This member function returns the default instance of the must be in use parameter. Modeling objects that are created will point to this instance, which can thus be shared between several objects.

This member function returns the time origin. The time origin and the time horizon are used by default at extraction to initialize the time window over which resource capacity constraints must be enforced. The origin and horizon are also used for setting earliest start times and latest end times of activities when they are created.

This member function returns the default instance of the possible states parameter. Modeling objects that are created will point to this instance, which can thus be shared between several objects.

This member function returns the global precedence enforcement level of the scheduler environment.

This member function returns the default instance of the resource parameter. Modeling objects that are created will point to this instance, which can thus be shared between several objects.

This member function returns the default instance of the transition time enforcement intervals parameter. Modeling objects that are created will point to this instance, which can thus be shared between several objects.

This member function sets param as the new default activity basic parameter. Subsequently created modeling objects will point to this parameter instance.

This member function sets param as the new default activity break parameter. Subsequently created modeling objects will point to this parameter instance.

This member function sets param as the new default activity constraints parameter. Subsequently created modeling objects will point to this parameter instance.

This member function sets param as the new default activity overlap parameter. Subsequently created modeling objects will point to this parameter instance.

This member function sets param as the new default activity shift parameter. Subsequently–created modeling objects will point to this parameter instance.

This member function sets param as the new default break list parameter. Subsequently created modeling objects will point to this parameter instance.

This member function sets param as the new default capacity enforcement intervals parameter. Subsequently created modeling objects will point to this parameter instance.

This member function sets param as the new default maximal capacity parameter. Subsequently created modeling objects will point to this parameter instance.

This member function sets param as the new default minimal capacity parameter. Subsequently created modeling objects will point to this parameter instance.

This member function sets the time horizon to horizon. The time origin and the time horizon are used by default at extraction to initialize the time window over which resource capacity constraints must be enforced. The origin and horizon are also used for setting earliest start times and latest end times of activities when they are created.

This member function sets param as the new default initial occupation parameter. Subsequently created modeling objects will point to this parameter instance.

This member function sets max as the new value for the maximum limit of the domain of the integer variables used by Scheduler Engine. See IloSchedulerEnv::getIntMaxAtExtraction for more information on avoiding overflows.

This member function sets the texture parameter on maximum capacity constraints to param. Modeling objects that are created will point to this instance, which can thus be shared between several objects.

This member function sets the texture parameter on minimum capacity constraints to param. Modeling objects that are created will point to this instance, which can thus be shared between several objects.

This member function sets param as the new default must be in use parameter. Subsequently created modeling objects will point to this parameter instance.

This member function sets the time origin to origin. The time origin and the time horizon are used by default at extraction to initialize the time window over which resource capacity constraints must be enforced. The origin and horizon are also used for setting earliest start times and latest end times of activities when they are created.

This member function sets param as the new default possible states parameter. Subsequently created modeling objects will point to this parameter instance.

This member function allows setting level as the new global precedence enforcement level of the scheduler environment. See Resource Enforcement as Global Constraint Declaration for a description of how this enforcement level is interpreted at extraction time by the scheduler engine.

This member function sets param as the new default resource parameter. Subsequently created modeling objects will point to this parameter instance.

This member function sets param as the new default transition time enforcement intervals parameter. Subsequently created modeling objects will point to this parameter instance.