logarithmicaxis.java

jfreechart安装程序和使用说明

     * 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");
                }
            }

            //change to log version of lowest value to make range
            // begin at a 10^n value:
            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();
            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
                upper = computeLogCeil(upper);  //use nearest log value
            }
            // 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) {
                    final double absUpper = Math.abs(upper);
                    //need to account for case where upper==0.0
                    final 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 state  the axis state.
     * @param drawArea  the area in which the plot and the axes should be drawn.
     * @param dataArea  the area in which the plot should be drawn.
     * @param edge  the location of the axis.
     * 
     * @return a list of ticks.
     */
    public List refreshTicks(Graphics2D g2, 
                             AxisState state,
                             Rectangle2D drawArea, 
                             Rectangle2D dataArea,
                             RectangleEdge edge) {

        List ticks = new java.util.ArrayList();
        if (RectangleEdge.isTopOrBottom(edge)) {
            ticks = refreshTicksHorizontal(g2, state.getCursor(), drawArea, dataArea, edge);
        }
        else if (RectangleEdge.isLeftOrRight(edge)) {
            ticks = refreshTicksVertical(g2, state.getCursor(), drawArea, dataArea, edge);
        }
        return ticks;

    }

    /**
     * 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 cursor  the cursor position.
     * @param drawArea  the area in which the plot and the axes should be drawn.
     * @param dataArea  the area in which the plot should be drawn.
     * @param edge  the location of the axis.
     * 
     * @return A list of ticks.
     */
    public List refreshTicksHorizontal(Graphics2D g2, 
                                       double cursor, 
                                       Rectangle2D drawArea, 
                                       Rectangle2D dataArea,
                                       RectangleEdge edge) {
        
        List ticks = new java.util.ArrayList();
//        FontMetrics fm = g2.getFontMetrics(getTickLabelFont());
        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
        final 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:
        final 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
          --iBegCount;       //decrement to generate more ticks
        }

        double currentTickValue;
        String tickLabel;
        boolean zeroTickFlag = false;
        for (int i = iBegCount; i <= iEndCount; i++) {
            //for each power of 10 value; create ten ticks
            for (int j = 0; j < 10; ++j) {
                //for each tick to be displayed
                if (this.smallLogFlag) {
                    //small log values in use; create numeric value for tick
                    currentTickValue = Math.pow(10, i) + (Math.pow(10, i) * j);
                    if (this.expTickLabelsFlag 
                        || (i < 0 && currentTickValue > 0.0 && currentTickValue < 1.0)) {
                        //showing "1e#"-style ticks or negative exponent
                        // generating tick value between 0 & 1; show fewer
                        if (j == 0 || (i > -4 && j < 2)
                                   || currentTickValue >= upperBoundVal) {
                          //first tick of series, or not too small a value and
                          // one of first 3 ticks, or last tick to be displayed
                               //set exact number of fractional digits to be shown
                               // (no effect if showing "1e#"-style ticks):
                            this.numberFormatterObj.setMaximumFractionDigits(-i);
                               //create tick label (force use of fmt obj):
                            tickLabel = makeTickLabel(currentTickValue, true);
                        }
                        else {    //no tick label to be shown
                            tickLabel = "";
                        }
                    }
                    else {     //tick value not between 0 & 1
                               //show tick label if it's the first or last in
                               // the set, or if it's 1-5; beyond that show
                               // fewer as the values get larger:
                        tickLabel = (j < 1 || (i < 1 && j < 5) || (j < 4 - i) 
                                           || currentTickValue >= upperBoundVal) 
                                           ? makeTickLabel(currentTickValue) : "";
                    }
                }
                else { //not small log values in use; allow for values <= 0
                    if (zeroTickFlag) {   //if did zero tick last iter then
                        --j;              //decrement to do 1.0 tick now
                    }     //calculate power-of-ten value for tick:
                    currentTickValue = (i >= 0)
                        ? Math.pow(10, i) + (Math.pow(10, i) * j)
                        : -(Math.pow(10, -i) - (Math.pow(10, -i - 1) * j));
                    if (!zeroTickFlag) {    //did not do zero tick last iteration
                        if (Math.abs(currentTickValue - 1.0) < 0.0001
                            && lowerBoundVal <= 0.0 && upperBoundVal >= 0.0) {
                            //tick value is 1.0 and 0.0 is within data range
                            currentTickValue = 0.0;     //set tick value to zero
                            zeroTickFlag = true;        //indicate zero tick
                        }
                    }
                    else {     //did zero tick last iteration
                        zeroTickFlag = false;         //clear flag
                    }               //create tick label string:
                               //show tick label if "1e#"-style and it's one
                               // of the first two, if it's the first or last
                               // in the set, or if it's 1-5; beyond that
                               // show fewer as the values get larger:
                    tickLabel = ((this.expTickLabelsFlag && j < 2) 
                                || j < 1 
                                || (i < 1 && j < 5) || (j < 4 - i) 
                                || currentTickValue >= upperBoundVal) 
                                   ? makeTickLabel(currentTickValue) : "";
                }