Package ptolemy.actor.lib

Class MultiplyDivide

  • All Implemented Interfaces:
    java.lang.Cloneable, Actor, Executable, FiringsRecordable, Initializable, TypedActor, Changeable, Debuggable, DebugListener, Derivable, Instantiable, ModelErrorHandler, MoMLExportable, Moveable, Nameable
    public class MultiplyDivide
extends TypedAtomicActor

    A polymorphic multiplier and/or divider. This adder has two input ports, both of which are multiports, and one output port, which is not. The types on the ports are undeclared and will be resolved by the type resolution mechanism. Data that arrives on the input port named multiply will be multiplied, and data that arrives on the input port named divide will be divided. Any token type supporting multiplication and division can be used. In most domains, either input port can be left unconnected. Thus, to get a simple multiplier (with no division), just leave the divide input unconnected.

    Currently, the type system is quite liberal about the resolved types it will permit at the inputs. In particular, it may permit the multiply and divide inputs to resolve to types that cannot in fact be multiplied or divided. In these cases, a run-time error will occur. In the future, we hope that the type system will intercept such errors before run time.

    This actor does not require that each input channel have a token upon firing. It will multiply or divide available tokens at the inputs and ignore the channels that do not have tokens. It consumes at most one input token from each port. If no input tokens are available on the multiply inputs, then a numerator of one is assumed for the division operations. The "one" is obtained by calling the one() method of the first token seen at the divide input. If no input tokens are available at all, then no output is produced.

    Since:
    Ptolemy II 0.3
    Version:
    $Id$
    Author:
    Edward A. Lee
    Pt.AcceptedRating:
    Green (bilung)
    Pt.ProposedRating:
    Green (eal)

    • Field Detail

      • divide

        public TypedIOPort divide
        Input for tokens to be divided. This is a multiport, and its type is inferred from the connections.

      • output

        public TypedIOPort output
        Output port. The type is inferred from the connections.

      • multiply

        public TypedIOPort multiply
        Input for tokens to be multiplied. This is a multiport, and its type is inferred from the connections.

    • Method Detail

      • fire

        public void fire()
          throws IllegalActionException
        If there is at least one token on the input ports, multiply tokens from the multiply port, divide by tokens from the divide port, and send the result to the output port. At most one token is read from each channel, so if more than one token is pending, the rest are left for future firings. If none of the input channels has a token, do nothing. If none of the multiply channels have tokens, then the tokens on the divide channels are divided into a one token of the same type as the denominator.
        Specified by:
        fire in interface Executable
        Overrides:
        fire in class AtomicActor<TypedIOPort>
        Throws:
        IllegalActionException - If there is no director, or if multiplication and division are not supported by the available tokens.