Package ptolemy.moml.unit

Class 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:
    $Id$
    Author:
    Rowland R Johnson
    Pt.AcceptedRating:
    Red (cxh)
    Pt.ProposedRating:
    Red (cxh)

    • Constructor Summary

      Constructors 
      Constructor Description
      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.

    • 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.

      • 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