Package ptolemy.data.ontologies

Class ExpressionConceptFunction

  • public class ExpressionConceptFunction
extends ConceptFunction

    This is a class for concept functions that are used specified using an expression from a ConceptFunctionDefinitionAttribute. The expression is evaluated with the input arguments to evaluate the concept function.

    An expression that represents a concept function is a boolean if-then expression that has multiple conditional statements that specifies the output concept value based on the input concept valuesof the arguments. Example: consider a function that has two arguments arg1 and arg2, and each argument can be a concept from the DimensionSystem ontology which has the possible Concept values:
    {Unknown, Dimensionless, Time, Position, Velocity, Acceleration, Conflict}

    A valid expression concept function could be defined like this:
    f(arg1, arg2) =
       arg1 == Unknown || arg2 == Unknown ? Unknown :
         arg1 == Position && arg2 == Time ? Velocity :
           arg1 == Velocity && arg2 == Time ? Acceleration :
             Conflict

    This expression function specifies that the output of the function is Unknown if either argument is Unknown, Velocity if arg1 is Position and arg2 is Time, Acceleration if arg1 is Velocity and arg2 is Time, and Conflict if arg1 and arg2 are any other combination of concept values.

    Since:
    Ptolemy II 10.0
    Version:
    $Id$
    Author:
    Charles Shelton
    Pt.AcceptedRating:
    Red (cshelton)
    Pt.ProposedRating:
    Green (cshelton)

    • Constructor Detail

      • ExpressionConceptFunction

        public ExpressionConceptFunction​(java.lang.String name,
                                 boolean numArgsIsFixed,
                                 java.util.List<Ontology> argumentDomainOntologies,
                                 Ontology outputRangeOntology,
                                 java.util.List<java.lang.String> argumentNames,
                                 java.lang.String conceptFunctionExpression,
                                 OntologySolverModel solverModel,
                                 NamedObj functionScopeModelElement)
                          throws IllegalActionException
        Initialize the expression concept function with the number of arguments it takes, the ontologies from which input and output concepts can be taken, the name of the function, and the string boolean expression that defines the function.
        Parameters:
        numArgsIsFixed - True if the number of arguments for this function is fixed and cannot change, false otherwise.
        argumentDomainOntologies - The array of ontologies that represent the concept domain for each input concept argument.
        outputRangeOntology - The ontology that represents the range of output concepts for this concept function.
        name - The string name used to identify this concept function.
        argumentNames - The list of strings that represent the names of the arguments to be used in parsing the concept function expression.
        conceptFunctionExpression - A string representing the boolean expression that defines the concept function.
        solverModel - The ontology solver model that contains other concept function definitions that could be called by the function defined in this expression.
        functionScopeModelElement - knk.
        Throws:
        IllegalActionException - If the ontology inputs are null or the length of the array of domain ontologies does not match the number of arguments for the function.

    • Method Detail

      • _evaluateFunction

        protected Concept _evaluateFunction​(java.util.List<Concept> inputConceptValues)
                             throws IllegalActionException
        Return the output of the concept function based on the concept inputs. This method evaluates the expression string using the concept inputs and the argument names array.
        Specified by:
        _evaluateFunction in class ConceptFunction
        Parameters:
        inputConceptValues - The array of concept inputs to the function.
        Returns:
        The concept output result of the function.
        Throws:
        IllegalActionException - If there is an error evaluating the function.