MultiObjectiveOptimizer Object

The MultiObjectiveOptimizer object provides functionality for defining and solving multi-objective optimization problems, enabling the analysis of solution spaces for applications such as trajectory design, contact planning, and more. This object supports the configuration of continuous or integer state variables, the definition of multiple minimizing or maximizing objectives, and the execution of stochastic solution methods using built-in SPEA, NSGA, or brute-force optimization engines. The MultiObjectiveOptimizer manages the iterative process of updating state variables, evaluating objective functions, and building a Pareto front of optimal solutions, and provides tools for filtering, sorting, and retrieving results. See the Using the Multi-Objective Optimizer Guide for more information.

Available In Editions:

Timing Precision Mode

Name	Description	Attributes
ContinuousStateVariables	The continuous state variables in the optimization process. Continuous state variables can have any real value between or equal to their lower and upper bounds.	Type: Array of MultiObjectiveOptimizationStateVariable Access: Read-Only
DeclaredName	The name of the object as declared.	Type: String Access: Read-Only
DisplayName	The name displayed for this object in output windows such as views, plots, and reports.	Type: String Access: Read/Write
EvaluatedSolutionCacheSize	The number of evaluated solutions to cache. This allows the optimizer to detect and skip re-evaluating solutions that are already in the cache. A larger cache size may increase or decrease the MultiObjectiveOptimizer's execution time depending on the problem being solved. When the value of this property is 0 the cache is disabled.	Type: Variable Access: Read/Write
EvaluationCount	The total number of evaluations of the objective values that have occurred.	Type: Variable Access: Read-Only
GenerationCount	The number of generations that have been evaluated.	Type: Variable Access: Read-Only
HypervolumeStallTolerance	When the average percent change in the Pareto front hypervolume over the last N generations is less than this tolerance the optimization process will terminate. N is equal to the value of the MultiObjectiveOptimizer.HypervolumeStallWindow property. The MultiObjectiveOptimizer.ParetoFront.HypervolumeStallMetric property can be used to track the value of the computation relative to this threshold. Note: when only one objective is present the hypervolume will always be zero and the hypervolume stall exit condition will never be triggered.	Type: Variable Access: Read/Write
HypervolumeStallWindow	The value of this property determines the number of past generational hypervolume values to include in the computation of the hypervolume stall value. The hypervolume stall exit condition can be disabled by setting this property zero. See the MultiObjectiveOptimizer.HypervolumeStallTolerance property for more information.	Type: Variable Access: Read/Write
IntegerStateVariablePermutationCount	The total number of permutations needed to represent every possible combination of the integer state variables in the MultiObjectiveOptimizer.IntegerStateVariables property.	Type: Variable Access: Read-Only
IntegerStateVariables	The integer state variables in the optimization process. Integer state variables can have any real integer value between or equal to their lower and upper bounds.	Type: Array of MultiObjectiveOptimizationStateVariable Access: Read-Only
MaximumConsecutiveStalledGenerations	The maximum allowed number of consecutive stalled generations. A stalled generation is one in which the pareto front is not advanced because no new non-dominated solutions are found. When the maximum number of stalled generations is reached, the optimization process is terminated. The generation stall exit condition can be disabled by setting this property zero.	Type: Variable Access: Read/Write
MaximumGenerations	The maximum number of generations to evaluate. When the maximum number of generations is reached the optimization process is terminated.	Type: Variable Access: Read/Write
ObjectId	The unique identifier for the object.	Type: Variable Access: Read-Only
ObjectType	The type of the object.	Type: String Access: Read-Only
OptimizationPhase	Reports the phase of the optimization process, which indicates whether the current evaluation is associated with the first member of a new generation.	Type: Variable Access: Read-Only
ParetoFront	The ParetoFront object holds the set of nondominated solutions found by the MultiObjectiveOptimizer. The Pareto front can be cleared using the MultiObjectiveOptimizer.Reset method.	Type: ParetoFront Access: Read-Only
PopulationSize	The number of solutions that will be processed in each generation.	Type: Variable Access: Read/Write
ReturnString	Holds the reason for optimization process termination. If the optimization process has not terminated this property will hold nothing.	Type: String Access: Read-Only
SolutionMutationRate	The percentage of the population that will be selected for mutation when generating the next generation of solutions. If this value is non-zero, at least one solution will be selected.	Type: Variable Access: Read/Write
StateVariableCrossoverRate	The percentage of individual variables within solutions that will be selected for crossover when generating the next generation of solutions. The value of each state variable in a particular solution represents a gene. This value is applied to both the continuous and integer variables independently. If this value is non-zero, at least one state variable will always be included in the crossover process.	Type: Variable Access: Read/Write
StateVariableMutationRate	The percentage of individual variables within a solution that will be selected for mutation when generating the next generation of solutions. The value of each state variable in a particular solution represents a gene. This value is applied to both the continuous and integer variables independently. If this value is non-zero, at least one state variable will always be included in the crossover process.	Type: Variable Access: Read/Write

Name	Description
AddContinuousStateVariable	Creates a new entry in the MultiObjectiveOptimizer.ContinuousStateVariables array with the specified label.
AddContinuousStateVariableBlock	Creates 'n' new entries in the MultiObjectiveOptimizer.ContinuousStateVariables array. Label is used as a prefix to create incremented labels for each entry. Continuous state variables can have any real value between or equal to their lower and upper bounds.
AddIntegerStateVariable	Creates a new entry in the MultiObjectiveOptimizer.IntegerStateVariables array with the specified label. Integer state variables can have any real integer value between or equal to their lower and upper bounds.
AddIntegerStateVariableBlock	Creates 'n' new entries in the MultiObjectiveOptimizer.IntegerStateVariables array. Label is used as a prefix to create incremented labels for each entry. Integer state variables can have any real integer value between or equal to their lower and upper bounds.
AddMaximizingObjective	Adds an objective to the multi-objective optimization problem. The optimizer will attempt to find solutions that maximize the value of this objective. The value of the objective must be set using the MultiObjectiveOptimizer.Maximize method inside the evaluation loop.
AddMinimizingObjective	Adds an objective to the multi-objective optimization problem. The optimizer will attempt to find solutions that minimize the value of this objective. The value of the objective must be set using the MultiObjectiveOptimizer.Maximize method inside the evaluation loop.
ClearSavedStates	Clears previous saved states for this object.
GetContinuousStateVariable	Returns a reference to the specified continuous state variable.
GetContinuousStateVariableValue	Returns the current value of the requested continuous state variable. Continuous state variables can have any real value between or equal to their lower and upper bounds. The current value is updated upon every call to MultiObjectiveOptimizer.UpdateStateVariables.
GetFromFile	Load the object state from the specified FreeFlyer object file.
GetFromString	Load the object state from the specified string.
GetIntegerStateVariable	Returns a reference to the specified integer state variable.
GetIntegerStateVariableValue	Returns the current value of the requested integer state variable. Integer state variables can have any real value between or equal to their lower and upper bounds. The current value is updated upon every call to MultiObjectiveOptimizer.UpdateStateVariables.
IsRunning	Returns 1 if the optimizer is currently running, otherwise returns 0.
LoadEngine	Loads and initializes the engine to be used in the optimization process. When this method is called, the engine is configured to process the specified state variables.
Maximize	Sets the value of the specified maximizing objective. This method should be called inside the multi-objective optimization evaluation loop so that the value of the specified objective is updated during each execution of the loop.
Minimize	Sets the value of the specified minimizing objective. This method should be called inside the multi-objective optimization evaluation loop so that the value of the specified objective is updated during each execution of the loop.
PutToFile	Convert the object state to FreeFlyer object xml and write to a file.
PutToString	Convert the object state to FreeFlyer object xml and return as a string.
ReferenceEquals	Returns 1 if the argument refers to the calling object and 0 otherwise.
RemoveAllObjectives	Removes all minimizing and maximizing objectives from the MultiObjectiveOptimizer.
Reset	Resets the optimization process.
Restore	Restore an object's state from a previously saved state.
RestoreObjectsInProcess	Restores all objects that have been saved using the Optimizer.SaveObjectToProcess() method.
Save	Save the object's state so that it can be restored later.
SaveObjectToProcess	Saves the initial state of the object. The object will be restored to this initial state whenever the Optimizer.RestoreObjectsInProcess() method is called.
UpdateStateVariables	Retrieves the next iteration of state variable values from the optimization process so that they can be subsequently used for evaluating the objective values. A call to this method should be placed at the top of the multi-objective optimization evaluation loop.

MultiObjectiveOptimizer Object

Description

Available In Editions:

Timing Precision Mode