ptolemy.data.expr

Class MatlabUtilities

java.lang.Object

ptolemy.data.expr.MatlabUtilities

public class MatlabUtilities
extends java.lang.Object

This class provides access to the Ptolemy Matlab interface in ptolemy.matlab by using reflection.

Since:

Ptolemy II 2.1

Version:

$Id$

Author:

Christopher Hylands, Steve Neuendorffer, Zoltan Kemenczy, Research in Motion Ltd.

See Also:

ParseTreeEvaluator

Pt.AcceptedRating:

Yellow (neuendor)

Pt.ProposedRating:

Green (neuendor)

Constructor Summary

Constructors

Constructor and Description
MatlabUtilities()

Method Summary

Modifier and Type	Method and Description
static Token	evaluate(java.lang.String expression, java.util.Set variableNames, ParserScope scope) Evaluate a Matlab expression within a scope.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MatlabUtilities

public MatlabUtilities()

Method Detail

evaluate

public static Token evaluate(java.lang.String expression,
                             java.util.Set variableNames,
                             ParserScope scope)
                      throws IllegalActionException

Evaluate a Matlab expression within a scope. The expression argument is of the form matlab("expression", arg1, arg2, ...), where arg1, arg2, ... is a list of Variables appearing in "expression". Note that this form of invoking matlab is limited to returning only the first return value of a matlab function. If you need multiple return values, use the matlab actor.

Note that having an instance of Expression in the model will keep the matlab engine open from model preinitialize() to wrapup() and hence opening/closing of additional Engine instances done by this matlab expression evaluator becomes fast. Most users should prefer to use Expression and resort to this mechanism of invoking matlab only where necessary, e.g. in FSM transition action expressions (which was the reason for introducing this form of matlab engine access).

If a "packageDirectories" Parameter is in the scope of this expression, its value is added to the matlab path while the expression is being executed (like Expression).

Parameters:

expression - The Matlab expression to be evaluated

variableNames - The Matlab variables required for evaluating the expression. Each element of the Set names a Token that is found in the scope.

scope - The scope to evaluate the expression within.

Returns:

The results of the evaluation

Throws:

IllegalActionException - If there is a problem initializing the Matlab interface, invoking the Matlab engine or accessing a a Token.