Calculation Objects - Script

Script components are a subset of Calculation Object components. They include Custom Functions and MATLAB, VBScript, Perl, or JScript Inline Functions.

Syntax

ComponentBrowser */ SetValue "Calculation Objects" {Component} {Attribute} <Value> [{Unit}]

ComponentBrowser */ Duplicate "Calculation Objects" {Component} <Duplicate Component Name>

Description

The Script components are:

Component	Description
CustomFunctionCalcObject	Calculation produced by a Custom Function. See more details in the Custom Functions table below.
JScript	Calculation produced by a JScript inline function
MATLAB	Calculation produced by a MATLAB inline function
Perl	Calculation produced by a Perl inline function
VBScript	Calculation produced by a VBScript inline function

The attributes for each component have the same names and value selections that appear in the Astrogator graphical user interface.

To use any MATLAB function, even an in-line function, you must be able to connect to MATLAB; STK will automatically start a session and connect when required. Inline functions are used for very simple computations that are not presently available as Calculation Objects in the Component Browser. They have three attributes:

CalcArguments
InlineFunc
UnitDimension

When an inline Calculation Object is used, STK creates a function with the inputs listed in CalcArguments, returning the value computed by the InlineFunc, with a name derived from the Calculation Object name itself.

Custom Functions

Astrogator makes the following custom functions available:

Function	Description
MATLAB Custom Function	A custom function implemented using a MATLAB M-file.
MATLAB DLL Custom Function	A custom function implemented using a MATLAB DLL.
Perl Custom Function	A custom function implemented using a Perl script.
Python Custom Function	A custom function implemented using a Python script.
Script Engine Custom Function	A custom function implemented using an IScriptEngine interface.
VB Script Custom Function	A custom function implemented using Visual Basic Script.

These functions can be used, for example, in defining Propagators, Engines, and Calculation Objects. The interfaces for these functions can be found in Plugin Scripts.

MATLAB DLL Functions

In order to produce a MATLAB DLL function that will be compatible with Astrogator, you must meet the following conditions:

You must have MATLAB version 6.5 installed on your system, and it must be installed on your system path before any later versions of MATLAB.
You must run the file "mccDll2Stk.m" before compiling any DLL functions. The file is located in the STK install folder under STKData\Scripting\Init.
The name of the function and the .m file that you produce must be entirely lower case, except for the first letter, which must be upper case.

Examples

Duplicating a Script component

ComponentBrowser */ Duplicate "Calculation Objects" Perl "My Perl"

Changing an attribute of a custom Script component

ComponentBrowser */ SetValue "Calculation Objects" "My CustomFunctionCalcObject" UnitDimension Temperature

STK Programming Interface 11.0.1