Examples of ptolemy.math.FixPoint

ptolemy.math.FixPoint
The FixPoint class provides a fixed point data type and a set of functions that operate on and return fixed point data. An instance of the class is immutable, meaning that its value is set in the constructor and cannot then be modified. This is similar to the Java built-in classes like Double, Integer, etc.
The FixPoint class represents signed numbers in a two's-complement format or unsigned numbers in a binary format with unlimited dynamic range and a resolution defined by a finite number of fractional bits. The precision is defined by the {@link ptolemy.math.Precision Precision} class.
Because a fixed point data type uses a finite number of bits to represent a value, a real value is converted to a number that can be expressed with a given precision of the fixed point, thereby introducing a quantization error. The overflow and rounding strategies used for this quantization are defined by an instance of the {@link ptolemy.math.Quantization Quantization} class.
The design of the FixPoint class complies with a philosophy that all operators work losslessly, i.e. the fractional precision of the result is determined such there is no loss of precision. To insure lossless operations, the resulting Precision of these operators will expand as necessary. Subsequent results can be quantized as necessary.
Violations of the loss-less philosophy occur during construction, division and conversion to floating point. During construction from floating point values, the nearest fixed point representation is created. The preferred divide operator provides for explicit specification of the quantization. A deprecated divide operator guesses at the result precision. Conversion to floating point is limited by the available floating point accuracy.
The FixPoint implementation uses the Java class BigInteger to represent the finite value and so this implementation is truly platform independent. Note that the FixPoint does not put any restrictions on the maximum number of bits in the representation of a value. @author Bart Kienhuis, Ed Willink, Contributor: Edward A. Lee, Mike Wirthlin @version $Id: FixPoint.java,v 1.84 2007/12/07 06:30:32 cxh Exp $ @since Ptolemy II 0.4, rewritten for Ptolemy II 2.2 @Pt.ProposedRating Red (Ed.Willink) @Pt.AcceptedRating Red @see ptolemy.math.Precision @see ptolemy.math.Quantization


                Rounding rounding = Rounding
                        .getName(((Parameter) getAttribute("outputRounding"))
                                .getExpression().toLowerCase());


                FixPoint result = new FixPoint(((ScalarToken) valuesArray
                        .getElement(_currentIndex)).doubleValue(),
                        new FixPointQuantization(precision, overflow, rounding));
                sendOutput(output, 0, new FixToken(result));
                _outputProduced = true;
            }

View Full Code Here

            BigInteger intResult = null;
            Precision precision = new Precision(
                    ((Parameter) getAttribute("outputPrecision"))
                            .getExpression());
            if (A.hasToken(0) && B.hasToken(0)) {
                FixPoint valueA = ((FixToken) A.get(0)).fixValue();
                FixPoint valueB = ((FixToken) B.get(0)).fixValue();
                if (valueA.getPrecision().getNumberOfBits() != precision
                        .getNumberOfBits()) {
                    throw new IllegalActionException(this,
                            "Input A has different width than the output port");
                }
                if (valueB.getPrecision().getNumberOfBits() != precision
                        .getNumberOfBits()) {
                    throw new IllegalActionException(this,
                            "Input B has different width than the output port");
                }
                BigInteger bigIntA = valueA.getUnscaledValue();
                BigInteger bigIntB = valueB.getUnscaledValue();
                if (operation.getExpression().equals("AND")) {
                    intResult = bigIntA.and(bigIntB);
                } else if (operation.getExpression().equals("OR")) {
                    intResult = bigIntA.or(bigIntB);
                } else if (operation.getExpression().equals("NAND")) {
                    intResult = bigIntA.and(bigIntB).not();
                } else if (operation.getExpression().equals("NOR")) {
                    intResult = bigIntA.or(bigIntB).not();
                } else if (operation.getExpression().equals("XOR")) {
                    intResult = bigIntA.xor(bigIntB);
                } else if (operation.getExpression().equals("XNOR")) {
                    intResult = bigIntA.xor(bigIntB).not();
                }
            }


            if (intResult != null) {
                Overflow overflow = Overflow
                        .getName(((Parameter) getAttribute("outputOverflow"))
                                .getExpression().toLowerCase());


                Rounding rounding = Rounding
                        .getName(((Parameter) getAttribute("outputRounding"))
                                .getExpression().toLowerCase());
                FixPoint result = new FixPoint(intResult.doubleValue(),
                        new FixPointQuantization(precision, overflow, rounding));
                sendOutput(output, 0, new FixToken(result));
            }
        } else {
            output.resend(0);

View Full Code Here


            // Consume tokens from all input ports.
            FixToken in = ((FixToken) dataIn.get(0));


            FixToken addressToken = (FixToken) address.get(0);
            FixPoint addressFixValue = addressToken.fixValue();


            FixToken writeEnableToken = (FixToken) writeEnable.get(0);
            FixPoint writeEnableValue = writeEnableToken.fixValue();


            _checkFixTokenWidth(writeEnableToken, 1);
            _checkFixTokenWidth(addressToken, _addressWidth);
            _checkFixTokenWidth(in, _dataWidth);


            addressValue = addressFixValue.getUnscaledValue().intValue();


            if (addressValue >= _capacity) {
                throw new IllegalActionException(this,
                        "Address is out of range.");
            }


            if (writeEnableValue.toBitString().equals("1")) {
                _storage[addressValue] = in;
            }


            Token result = _storage[addressValue];
            if (result == null) {

View Full Code Here

     *  @param integerBits The number of bits used for the integer part.
     *  @return a double with value that is quantized.
     */
    public static double quantize(double value, int numberOfBits,
            int integerBits) {
        FixPoint fixValue = Quantizer.round(value, new Precision(numberOfBits,
                integerBits));
        return fixValue.doubleValue();
    }

View Full Code Here

                    _currentCount = 0;
                }
            }


            // Produce an output if we consumed an input.
            FixPoint result = new FixPoint(_currentCount);
            Token outputToken = new FixToken(result);
            sendOutput(output, 0, outputToken);


        } else {

View Full Code Here

        super.fire();
        BigInteger intResult = null;
        int bitsInResult = 0;


        if (A.isKnown() && A.hasToken(0)) {
            FixPoint valueA = ((FixToken) A.get(0)).fixValue();
            bitsInResult = valueA.getPrecision().getNumberOfBits();
            BigInteger bigIntA = valueA.getUnscaledValue();
            intResult = bigIntA.not();
            Precision precision = new Precision(1, bitsInResult, 0);
            FixToken result = new FixToken(intResult.doubleValue(), precision);
            sendOutput(output, 0, result);
        } else {

View Full Code Here


        Rounding rounding = Rounding
                .getName(((Parameter) getAttribute("outputRounding"))
                        .getExpression().toLowerCase());


        FixPoint result = new FixPoint(((ScalarToken) value.getToken())
                .doubleValue(), new FixPointQuantization(precision, overflow,
                rounding));


        sendOutput(output, 0, new FixToken(result));
    }

View Full Code Here

     * @exception IllegalActionException If there is no director.
     */
    public void fire() throws IllegalActionException {
        super.fire();
        FixToken in = (FixToken) input.get(0);
        FixPoint value = in.fixValue();
        output.send(0, new DoubleToken(value.doubleValue()));
    }

View Full Code Here

     *  @exception IllegalActionException If there is no director.
     */
    public void fire() throws IllegalActionException {
        super.fire();
        DoubleToken in = (DoubleToken) input.get(0);
        FixPoint fixValue = new FixPoint(in.doubleValue(), _quantization);
        FixToken result = new FixToken(fixValue);
        output.send(0, result);
    }

View Full Code Here

     *  @exception IllegalActionException If there is no director.
     */
    public void fire() throws IllegalActionException {
        super.fire();
        FixToken in = (FixToken) input.get(0);
        FixPoint fixValue = in.fixValue().quantize(_quantization);
        FixToken result = new FixToken(fixValue);
        output.send(0, result);
    }

View Full Code Here

0 1 2 3

TOP

Related Classes of ptolemy.math.FixPoint

ptolemy.actor.lib.conversions.DoubleToFix

ptolemy.actor.lib.conversions.FixToDouble

ptolemy.actor.lib.conversions.FixToFix

ptolemy.actor.lib.vhdl.Concat

ptolemy.actor.lib.vhdl.FixConst

ptolemy.actor.lib.vhdl.FixCounter

ptolemy.actor.lib.vhdl.FixSequence

ptolemy.actor.lib.vhdl.FixToString

ptolemy.actor.lib.vhdl.IntegerCounter

ptolemy.actor.lib.vhdl.LogicalNot

All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.