logarithmicaxis.java

java图形利器

            //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 switchedPow10(axisMax - ((java2DValue - plotMin) 
                    / (plotMax - plotMin)) * (axisMax - axisMin));
        }
        else {
            return switchedPow10(axisMin + ((java2DValue - plotMin) 
                    / (plotMax - plotMin)) * (axisMax - axisMin));
        }
    }

    /**
     * Zooms in on the current range.
     * 
     * @param lowerPercent  the new lower bound.
     * @param upperPercent  the new upper bound.
     */
    public void zoomRange(double lowerPercent, double upperPercent) {
        double startLog = switchedLog10(getRange().getLowerBound());
        double lengthLog = switchedLog10(getRange().getUpperBound()) -
                           startLog;
        Range adjusted;

        if (isInverted()) {
            adjusted = new Range(
                    switchedPow10(
                            startLog + (lengthLog * (1 - upperPercent))),
                    switchedPow10(
                            startLog + (lengthLog * (1 - lowerPercent))));
        } 
        else {
            adjusted = new Range(
                    switchedPow10(startLog + (lengthLog * lowerPercent)),
                    switchedPow10(startLog + (lengthLog * upperPercent)));
        }

        setRange(adjusted);
    }

    /**
     * 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
            --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