Single Parameter Bisection Profile

The bisection profile is a search profile that is a simple, single-parameter targeting option. To configure a bisection profile, you select control parameters and results on nested segments. Unlike other search profiles, a bisection profile is limited to one parameter and one result. The profile will first attempt to bound a goal value of the result. If it is successful, the profile will then bisect the difference in the control parameter. It will continue to do this until the result value falls within the specified tolerance.

The bisection search profile dialog box comprises five tabs:

• Variables
• Options
• Log
• Graphs
• Scripting

Variables

There are two types of variables in a bisection search profile:

• Controls (independent variables)
• Results (dependent variables)

The control parameters and results that are selected for the target sequence are displayed on the Variables tab. Double-click a property of a control parameter or result to edit its value.

Controls (independent variables)

Any element of a nested MCS segment or linked component that you can use as an independent variable is marked by a target icon, . To select an element as an independent variable, click its target icon. A check mark appears over the target. Click the target again to clear the selection of that element.

The Restore nominal values as soon as target sequence completes MCS Option isolates changes in value. If the independent variable is an element of a linked component, this option has an important effect. Astrogator will only apply the changed value of the element to subsequent segments within the same target sequence. Segments that are outside the target sequence will use the value of the element at the beginning of the MCS. If you apply corrections after running the MCS, then on the next run all segments in the MCS will use the value produced by the target sequence.

Each independent variable that you select is listed in the Available Controls area, with the following information:

• Use - Select this option to enable the element as a control parameter.

If more than one control parameter is enabled when the profile is run, Astrogator will generate an error message in the message viewer.

• Object - The segment or component that the element belongs to.
• Name - The name of the element.
• Initial Value - The nominal value of the element.
• Current Value - The element's final value from the last run of the profile. If the profile has not run, this value is the same as the initial value.
• Custom Display Unit - Select this option to use a custom unit for the element in the status window and graphs.
• Display Unit - The unit to display if you have selected Custom Display Unit.

Graphs cannot display DMS or HMS angle units and will use the scenario unit instead.

If you have multiple independent variables, select Hide Inactive to hide the variables that are not selected.

Results (dependent variables)

Dependent variables are defined in terms of Calculation Objects. To select dependent variables for a nested MCS segment, select the segment and then click Results.... In the User-Selected Results dialog box, select the Calculation Objects to use.

Each dependent variable that you select is listed in the Available Results area, along with the following information:

• Use - Select this option to enable the result.

If more than one result is enabled when the profile is run, Astrogator will generate an error message in the message viewer.

• Object - The segment or component that the element belongs to.
• Name - The name of the element.
• Current Value - The element's final value from the last run of the profile. If the profile has not run, this value is the same as the initial value.
• Desired Value - The value that you want to achieve. To paste a value into this field, right-click it and select Paste.
• Tolerance - The profile will stop when it achieves a value within this range of the Desired Value.
• Custom Display Unit - Select this option to use a custom unit for the element in the status window and graphs.
• Display Unit - The unit to be displayed if you have selected Custom Display Unit.

Graphs cannot display DMS or HMS angle units and will use the scenario unit instead

If you have multiple dependent variables, select Hide Inactive to hide the variables that are not selected.

You can also edit the Desired Value and Tolerance properties of the selected dependent variable in fields that are displayed beneath the table.

Options

The Options tab contains one property that is specific to the bisection search profile: Maximum Iterations. This property defines the maximum number of evaluations that the profile executes. If the profile does not reach the Desired Value, it will stop after the last iteration. The iteration count includes steps taken while searching for bounds as well as bisection iterations.

Select Reset controls before each run to reset the profile's controls each time that Astrogator runs it. The profile will discard information that was computed the last time it was run.

Log

The bisection search profile's log contains information about the iteration history of the most recent run. The File name field displays the path and name of the log file. The log is saved to the scenario folder when the scenario is saved. Until then, Astrogator stores the log information in a temporary file. The log information - the raw output of the profile - displays below the file name. It can be useful for debugging or troubleshooting.

Graphs

The Graphs tab comprises controls that you can use to create and view graphs of the profile's performance. The upper pane contains a table of the graphs defined for the profile. The Graph Properties pane displays the collection of properties that you can use to define each graph. Select a graph in the table in the upper pane to view and define its properties here.

Graphs table

Using the toolbar, you can create new graphs or cut, copy, paste, or delete them.

Button	Name	Function
	New...	Insert a new graph with default properties settings.
	Cut	Move the selected graph from the list to the clipboard.
	Copy	Copy the selected graph to the clipboard.
	Paste	Insert a copy of the graph that is on the clipboard.
	Delete	Delete the selected graph.

The graphs table displays the name and description of each graph. Select Generate on run if you want Astrogator to generate the graph each time that it runs the MCS. You can right-click a graph to select the same commands that are available in the toolbar.

Graph properties

Each graph can display the values of any number of the active Controls and Results defined for the profile against an X axis of the number of iterations performed or any single active Control or Result defined for the profile.

The Independent variable field defines the X axis of the graph. If the X axis is an active Control or Result, select Label Iterations if you want to label the points on the graph by their iteration numbers. If the X axis is one of the active Results and the profile results have a DesiredValue property, you can select Show Desired Value to display its goal. Likewise, if the results have a Tolerance property, you can select Show Tolerance Band to display the tolerance for the Desired Value.

The active Controls defined for the profile are listed in a table. You can customize how they are displayed in the graph by directly clicking the property fields.

Property Field	Description
Name	This is the name of the element within the object.
Object	Identifies the segment or component that the element belongs to.
Graph Value	Select this option to include the value.
Line Color	The color of line that will be used to represent the control's value.
Point Style	The style of marker used to represent iteration points along the control's line.
Y Axis	Select Y1 or Y2 to display a range of values suitable to the control on the left or right side, respectively, of the graph.

The active Results defined for the profile are also listed in a table. You can customize how they are displayed in the graph by directly clicking the property fields.

Property Field	Description
Name	This is the name of the Calculation Object selected as a result item.
Object	Identifies the segment or component that the result item belongs to.
Graph Option	Select this option to include the value.
Show Desired Value	If the result has a DesiredValue property, select this option to display the result's desired value.
Line Color	The color of line that will be used to represent the control's value.
Point Style	The style of marker used to represent iteration points along the control's line.
Y Axis	Select Y1 or Y2 to display a range of values suitable to the control on the left or right side, respectively, of the graph.
Show Tolerance Band	If the result has a Tolerance property, select this option to display the tolerance for the result's desired value.

Click Generate Graph to produce the selected graph. To produce a report of the graph data, click Generate Report.

Scripting

The Scripting tab contains an embedded instance of the Scripting Tool. If you enter a script here, Astrogator will execute it before running the sequence each time Astrogator runs the sequence. You can use parameters that are defined in the Scripting Tool as controls by the profile.