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: MatlabUtilities.java 57040 2010-01-27 20:52:32Z cxh $

Author:

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

See Also:

ParseTreeEvaluator

Accepted Rating:

Yellow (neuendor)

Proposed Rating:

Green (neuendor)

Field Summary

private static long[]	_engine
private static java.lang.Class	_engineClass
private static java.lang.reflect.Method	_engineClose
private static java.lang.reflect.Method	_engineEvalString
private static java.lang.reflect.Method	_engineGet
private static java.lang.reflect.Method	_engineOpen
private static java.lang.reflect.Method	_enginePut

Constructor Summary

MatlabUtilities()

Method Summary

private static void	_initialize()
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

Field Detail

_engine

private static long[] _engine

_engineClass

private static java.lang.Class _engineClass

_engineClose

private static java.lang.reflect.Method _engineClose

_engineEvalString

private static java.lang.reflect.Method _engineEvalString

_engineGet

private static java.lang.reflect.Method _engineGet

_engineOpen

private static java.lang.reflect.Method _engineOpen

_enginePut

private static java.lang.reflect.Method _enginePut

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 elemement 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.

_initialize

private static void _initialize()
                         throws IllegalActionException

Throws:

IllegalActionException