logarithmicaxis.java

来自「JfreeChart 常用图表例子」· Java 代码 · 共 1,023 行 · 第 1/3 页

                : (Math.log(val) / LOG10_VALUE);
    }

    /**
     * Returns the largest (closest to positive infinity) double value that is
     * not greater than the argument, is equal to a mathematical integer and
     * satisfying the condition that log base 10 of the value is an integer
     * (i.e., the value returned will be a power of 10: 1, 10, 100, 1000, etc.).
     *
     * @param lower a double value below which a floor will be calcualted.
     *
     * @return 10<sup>N</sup> with N .. { 1 ... }
     */
    protected double computeLogFloor(double lower) {

        double logFloor;
        if (this.allowNegativesFlag) {
            //negative values are allowed
            if (lower > 10.0) {   //parameter value is > 10
                // The Math.log() function is based on e not 10.
                logFloor = Math.log(lower) / LOG10_VALUE;
                logFloor = Math.floor(logFloor);
                logFloor = Math.pow(10, logFloor);
            }
            else if (lower < -10.0) {   //parameter value is < -10
                //calculate log using positive value:
                logFloor = Math.log(-lower) / LOG10_VALUE;
                //calculate floor using negative value:
                logFloor = Math.floor(-logFloor);
                //calculate power using positive value; then negate
                logFloor = -Math.pow(10, -logFloor);
            }
            else {
                //parameter value is -10 > val < 10
                logFloor = Math.floor(lower);   //use as-is
            }
        }
        else {
            //negative values not allowed
            if (lower > 0.0) {   //parameter value is > 0
                // The Math.log() function is based on e not 10.
                logFloor = Math.log(lower) / LOG10_VALUE;
                logFloor = Math.floor(logFloor);
                logFloor = Math.pow(10, logFloor);
            }
            else {
                //parameter value is <= 0
                logFloor = Math.floor(lower);   //use as-is
            }
        }
        return logFloor;
    }

    /**
     * Returns the smallest (closest to negative infinity) double value that is
     * not less than the argument, is equal to a mathematical integer and
     * satisfying the condition that log base 10 of the value is an integer
     * (i.e., the value returned will be a power of 10: 1, 10, 100, 1000, etc.).
     *
     * @param upper a double value above which a ceiling will be calcualted.
     *
     * @return 10<sup>N</sup> with N .. { 1 ... }
     */
    protected double computeLogCeil(double upper) {

        double logCeil;
        if (this.allowNegativesFlag) {
            //negative values are allowed
            if (upper > 10.0) {
                //parameter value is > 10
                // The Math.log() function is based on e not 10.
                logCeil = Math.log(upper) / LOG10_VALUE;
                logCeil = Math.ceil(logCeil);
                logCeil = Math.pow(10, logCeil);
            }
            else if (upper < -10.0) {
                //parameter value is < -10
                //calculate log using positive value:
                logCeil = Math.log(-upper) / LOG10_VALUE;
                //calculate ceil using negative value:
                logCeil = Math.ceil(-logCeil);
                //calculate power using positive value; then negate
                logCeil = -Math.pow(10, -logCeil);
            }
            else {
               //parameter value is -10 > val < 10
               logCeil = Math.ceil(upper);     //use as-is
            }
        }
        else {
            //negative values not allowed
            if (upper > 0.0) {
                //parameter value is > 0
                // The Math.log() function is based on e not 10.
                logCeil = Math.log(upper) / LOG10_VALUE;
                logCeil = Math.ceil(logCeil);
                logCeil = Math.pow(10, logCeil);
            }
            else {
                //parameter value is <= 0
                logCeil = Math.ceil(upper);     //use as-is
            }
        }
        return logCeil;
    }

    /**
     * Rescales the axis to ensure that all data is visible.
     */
    public void autoAdjustRange() {

        Plot plot = getPlot();
        if (plot == null) {
            return;  // no plot, no data.
        }

        if (plot instanceof ValueAxisPlot) {
            ValueAxisPlot vap = (ValueAxisPlot) plot;

            double lower;
            Range r = vap.getDataRange(this);
            if (r == null) {
                   //no real data present
                r = new Range(DEFAULT_LOWER_BOUND, DEFAULT_UPPER_BOUND);
                lower = r.getLowerBound();    //get lower bound value
            }
            else {
                //actual data is present
                lower = r.getLowerBound();    //get lower bound value
                if (this.strictValuesFlag
                        && !this.allowNegativesFlag && lower <= 0.0) {
                    //strict flag set, allow-negatives not set and values <= 0
                    throw new RuntimeException(
                        "Values less than or equal to "
                        + "zero not allowed with logarithmic axis"
                    );
                }
            }

            //apply lower margin by decreasing lower bound:
            final double lowerMargin;
            if (lower > 0.0 && (lowerMargin=getLowerMargin()) > 0.0) {
                   //lower bound and margin OK; get log10 of lower bound
              final double logLower = (Math.log(lower) / LOG10_VALUE);
              double logAbs;      //get absolute value of log10 value
              if((logAbs=Math.abs(logLower)) < 1.0) {
                logAbs = 1.0;     //if less than 1.0 then make it 1.0
              }              //subtract out margin and get exponential value:
              lower = Math.pow(10, (logLower - (logAbs * lowerMargin)));
            }

            //if flag then change to log version of lowest value
            // to make range begin at a 10^n value:
           if (this.autoRangeNextLogFlag) {
               lower = computeLogFloor(lower);
           }

            if (!this.allowNegativesFlag && lower >= 0.0
                    && lower < SMALL_LOG_VALUE) {
                //negatives not allowed and lower range bound is zero
                lower = r.getLowerBound();    //use data range bound instead
            }

            double upper = r.getUpperBound();

             //apply upper margin by increasing upper bound:
            final double upperMargin;
            if (upper > 0.0 && (upperMargin=getUpperMargin()) > 0.0) {
                   //upper bound and margin OK; get log10 of upper bound
              final double logUpper = (Math.log(upper) / LOG10_VALUE);
              double logAbs;      //get absolute value of log10 value
              if((logAbs=Math.abs(logUpper)) < 1.0) {
                logAbs = 1.0;     //if less than 1.0 then make it 1.0
              }              //add in margin and get exponential value:
              upper = Math.pow(10, (logUpper + (logAbs * upperMargin)));
            }

            if (!this.allowNegativesFlag && upper < 1.0 && upper > 0.0
                    && lower > 0.0) {
                //negatives not allowed and upper bound between 0 & 1
                //round up to nearest significant digit for bound:
                //get negative exponent:
                double expVal = Math.log(upper) / LOG10_VALUE;
                expVal = Math.ceil(-expVal + 0.001); //get positive exponent
                expVal = Math.pow(10, expVal);      //create multiplier value
                //multiply, round up, and divide for bound value:
                upper = (expVal > 0.0) ? Math.ceil(upper * expVal) / expVal
                    : Math.ceil(upper);
            }
            else {
                //negatives allowed or upper bound not between 0 & 1
                //if flag then change to log version of highest value to
                // make range begin at a 10^n value; else use nearest int
                upper = (this.autoRangeNextLogFlag) ? computeLogCeil(upper)
                    : Math.ceil(upper);
            }
            // ensure the autorange is at least <minRange> in size...
            double minRange = getAutoRangeMinimumSize();
            if (upper - lower < minRange) {
                upper = (upper + lower + minRange) / 2;
                lower = (upper + lower - minRange) / 2;
                //if autorange still below minimum then adjust by 1%
                // (can be needed when minRange is very small):
                if (upper - lower < minRange) {
                    double absUpper = Math.abs(upper);
                    //need to account for case where upper==0.0
                    double adjVal = (absUpper > SMALL_LOG_VALUE) ? absUpper
                        / 100.0 : 0.01;
                    upper = (upper + lower + adjVal) / 2;
                    lower = (upper + lower - adjVal) / 2;
                }
            }

            setRange(new Range(lower, upper), false, false);
            setupSmallLogFlag();       //setup flag based on bounds values
        }
    }

    /**
     * Converts a data value to a coordinate in Java2D space, assuming that
     * the axis runs along one edge of the specified plotArea.
     * Note that it is possible for the coordinate to fall outside the
     * plotArea.
     *
     * @param value  the data value.
     * @param plotArea  the area for plotting the data.
     * @param edge  the axis location.
     *
     * @return The Java2D coordinate.
     */
    public double valueToJava2D(double value, Rectangle2D plotArea,
                                RectangleEdge edge) {

        Range range = getRange();
        double axisMin = switchedLog10(range.getLowerBound());
        double axisMax = switchedLog10(range.getUpperBound());

        double min = 0.0;
        double max = 0.0;
        if (RectangleEdge.isTopOrBottom(edge)) {
            min = plotArea.getMinX();
            max = plotArea.getMaxX();
        }
        else if (RectangleEdge.isLeftOrRight(edge)) {
            min = plotArea.getMaxY();
            max = plotArea.getMinY();
        }

        value = switchedLog10(value);

        if (isInverted()) {
            return max
                - (((value - axisMin) / (axisMax - axisMin)) * (max - min));
        }
        else {
            return min
                + (((value - axisMin) / (axisMax - axisMin)) * (max - min));
        }

    }

    /**
     * Converts a coordinate in Java2D space to the corresponding data
     * value, assuming that the axis runs along one edge of the specified
     * plotArea.
     *
     * @param java2DValue  the coordinate in Java2D space.
     * @param plotArea  the area in which the data is plotted.
     * @param edge  the axis location.
     *
     * @return The data value.
     */
    public double java2DToValue(double java2DValue, Rectangle2D plotArea,
                                RectangleEdge edge) {

        Range range = getRange();
        double axisMin = switchedLog10(range.getLowerBound());
        double axisMax = switchedLog10(range.getUpperBound());

        double plotMin = 0.0;
        double plotMax = 0.0;
        if (RectangleEdge.isTopOrBottom(edge)) {
            plotMin = plotArea.getX();
            plotMax = plotArea.getMaxX();
        }
        else if (RectangleEdge.isLeftOrRight(edge)) {
            plotMin = plotArea.getMaxY();
            plotMax = plotArea.getMinY();
        }

        if (isInverted()) {
            return Math.pow(
                10, axisMax - ((java2DValue - plotMin) / (plotMax - plotMin))
                * (axisMax - axisMin)
            );
        }
        else {
            return Math.pow(
                10, axisMin + ((java2DValue - plotMin) / (plotMax - plotMin))
                * (axisMax - axisMin)
            );
        }
    }

    /**
     * Calculates the positions of the tick labels for the axis, storing the
     * results in the tick label list (ready for drawing).
     *
     * @param g2  the graphics device.
     * @param dataArea  the area in which the plot should be drawn.
     * @param edge  the location of the axis.
     *
     * @return A list of ticks.
     */
    protected List refreshTicksHorizontal(Graphics2D g2,
                                          Rectangle2D dataArea,
                                          RectangleEdge edge) {

        List ticks = new java.util.ArrayList();
        Range range = getRange();

        //get lower bound value:
        double lowerBoundVal = range.getLowerBound();
              //if small log values and lower bound value too small
              // then set to a small value (don't allow <= 0):
        if (this.smallLogFlag && lowerBoundVal < SMALL_LOG_VALUE) {
            lowerBoundVal = SMALL_LOG_VALUE;
        }

        //get upper bound value
        double upperBoundVal = range.getUpperBound();

        //get log10 version of lower bound and round to integer:
        int iBegCount = (int) Math.rint(switchedLog10(lowerBoundVal));
        //get log10 version of upper bound and round to integer:
        int iEndCount = (int) Math.rint(switchedLog10(upperBoundVal));

        if (iBegCount == iEndCount && iBegCount > 0
                && Math.pow(10, iBegCount) > lowerBoundVal) {
              //only 1 power of 10 value, it's > 0 and its resulting
              // tick value will be larger than lower bound of data