Minimize

General Mission Analysis Tool

Minimize

Minimize — Define the cost function to minimize

Script Syntax

Minimize OptimizerName (ObjectiveFunction)

Description

The Minimize command is used within an Optimize/EndOptimize Optimization sequence to define the objective function that you want to minimize.

See Also: Vary, NonlinearConstraint, Optimize

Options

Option Description

ObjectiveFunction

Specifies the objective function that the optimizer will try to minimize.

Accepted Data Types	String
Allowed Values	Spacecraft parameter, Array element, Variable, or any other single element user defined parameter, excluding numbers
Default Value	`DefaultSC.Earth.RMAG`
Required	yes
Interfaces	GUI, script

OptimizerName

Specifies which optimizer to use to minimize the cost function

Accepted Data Types	Reference Array
Allowed Values	Any VF13ad or fminconOptimizer resource
Default Value	DefaultSQP
Required	yes
Interfaces	GUI, script

GUI

You use a Minimize command, within an Optimize/EndOptimize Optimization sequence as shown below, to define a cost function that you wish to minimize.

Double click on Minimize1 to bring up the Minimize command dialog box shown below..

You must provide two inputs for the Minimize command dialog box above:

Choice of optimizer.
Object (and associated variable) to be minimized. You can input an object directly or you can click the Edit button to the right of this field to select the type of object from three possible choices, Spacecraft, Variable, or Array.

Remarks

Number of Vary, NonlinearConstraint, and Minimize Commands Within an Optimization Sequence

An Optimization sequence must contain one or more Vary commands. Vary commands must occur before any Minimize or NonlinearConstraint commands.

At most, a single Minimize command is allowed within an optimization sequence.

It is possible for an Optimize/EndOptimize optimization sequence to contain no Minimize commands. In this case, since every optimization sequence must contain (a) one or more NonlinearConstraint commands and/or (b) a single Minimize command, the optimization sequence must contain at least one NonlinearConstraint command.

Command Interactions

The Minimize command is only used within an Optimize/EndOptimize Optimization sequence. See the Optimize command documentation for a complete worked example using the Minimize command.

Vary command	Every Optimization sequence must contain at least one Vary command. Vary commands are used to define the control variables associated with an Optimization sequence.
NonlinearConstraint command	NonlinearConstraint commands are used to define the constraints (i.e., goals) associated with an Optimization sequence. Note that multiple NonlinearConstraint commands are allowed within an Optimization sequence.
Optimize command	A Minimize command can only occur within an Optimize/EndOptimize command sequence.

Examples

% Minimize the eccentricity of Sat, using SQP1
Minimize SQP1(Sat.ECC)

% Minimize the Variable DeltaV, using SQP1
Minimize SQP1(DeltaV)

% Minimize the first component of MyArray, using VF13ad1
Minimize VF13ad1(MyArray(1,1))

As mentioned above, the Minimize command only occurs within an Optimize sequence. See the Optimize command help for complete examples showing the use of the Minimize command.

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