ptolemy.moml.unit
Class UnitConstraints

java.lang.Object
  ptolemy.moml.unit.UnitConstraints

All Implemented Interfaces:

UnitPresentation

public class UnitConstraints
extends java.lang.Object
implements UnitPresentation

UnitConstraints represents a group, with duplicates allowed, of UnitConstraints. The are two general ways to create an instance of this class. The first requires you to create an instance without any UnitConstraints and then add them with the method addConstraint. The second is to specify a TypedCompositeActor as well as specific nodes and relations in the TypedCompositeActor, and have the UnitConstraintCollection constructor determine which UnitConstraints belong to the collection.

Since:

Ptolemy II 8.0

Version:

$Id: UnitConstraints.java 57044 2010-01-27 22:41:05Z cxh $

Author:

Rowland R Johnson

Accepted Rating:

Red (cxh)

Proposed Rating:

Red (cxh)

Field Summary

private Bindings	_bindings
private java.util.Vector	_constraints
private boolean	_debug
private static ExpandPortNames	_equationVisitor
private TypedCompositeActor	_model

Constructor Summary

UnitConstraints()
Construct an empty collection of Unit constraints.

UnitConstraints(TypedCompositeActor model, java.util.Vector entities, java.util.Vector relations)
Construct a collection of Unit constraints from the specified componentEntities and relations of a model.

Method Summary

void	addConstraint(UnitConstraint constraint) Add a UnitConstraint to the collection.
Solution	completeSolution() Generate a complete solution.
java.lang.String	descriptiveForm() This method generates the descriptive form.
java.util.Vector	getConstraints() Get the constraints in the collection.
java.util.Vector	minimalSpanSolutions() Generate the minimal span solutions of the collection.

Methods inherited from class java.lang.Object

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

Methods inherited from interface ptolemy.moml.unit.UnitPresentation

toString

Field Detail

_bindings

private Bindings _bindings

_constraints

private java.util.Vector _constraints

_debug

private boolean _debug

_equationVisitor

private static ExpandPortNames _equationVisitor

_model

private TypedCompositeActor _model

Constructor Detail

UnitConstraints

public UnitConstraints()

Construct an empty collection of Unit constraints.

UnitConstraints

public UnitConstraints(TypedCompositeActor model,
                       java.util.Vector entities,
                       java.util.Vector relations)
                throws IllegalActionException

Construct a collection of Unit constraints from the specified componentEntities and relations of a model.

For each componentEntity each constraints in the form of Unit equation is retrieved and then used a basis to create a Unit constraint to add to the collection. Each port on the componentEntity is inspected to see if it has a Unit specified for it. If so, then that Unit specification is used to create a corresponding Unit constraint that gets added to the collection.

A component entity itself may have Unit constraint(s) that then get added to the collection. For example, the AddSubtract actor would likely have a constraint that requires that the plus, and minus ports be equal.

The relations are then considered. Any relation that connects two ports seen on a component entity in the first step is used to create a Unit equation that gets added to the collection.

Parameters:

model - The model containing the component entities.

entities - The component entities.

relations - The relations.

Throws:

IllegalActionException

Method Detail

addConstraint

public void addConstraint(UnitConstraint constraint)

Add a UnitConstraint to the collection.

Parameters:

constraint - The UnitConstraint to be added to the collection.

completeSolution

public Solution completeSolution()
                          throws IllegalActionException

Generate a complete solution.

Returns:

The solution.

Throws:

IllegalActionException

descriptiveForm

public java.lang.String descriptiveForm()

Description copied from interface: UnitPresentation

This method generates the descriptive form. In addition to the internal form used by the system Units, UnitConstraints, UnitExprs, etc. have a descriptive form that is used by humans. This method generates that form so that humans can easily understand the results generated by the system. For example, an internal representation of a Unit could be 4.1868E7*<2, 1, 1, 0, 0> and its descriptive form would be "calorie".

The descriptive form is invariant across Unit Systems. That is, calorie is calorie regardless of the Unit System. But, the internal form may be 4.1868E7*<2, 1, 1, 0, 0> in one Unit System, and 1.0*<2, 1, 1, 0, 0> in another. Therefore the descriptive form is used as the external representation. This makes it possible to save a model under one Unit System, and then load it under a different Unit System.

Specified by:

descriptiveForm in interface UnitPresentation

Returns:

The descriptive form.

See Also:

UnitPresentation.descriptiveForm()

getConstraints

public java.util.Vector getConstraints()

Get the constraints in the collection.

Returns:

The constraints.

minimalSpanSolutions

public java.util.Vector minimalSpanSolutions()
                                      throws IllegalActionException

Generate the minimal span solutions of the collection.

Returns:

The minimal span solutions.

Throws:

IllegalActionException