}

    /**
     * Sets the range axis for the plot.
     * <P>
     * An exception is thrown if the new axis and the plot are not mutually
     * compatible.
     *
     * @param axis The new axis (null permitted).
     */
    public void setRangeAxis(ValueAxis axis) {

        if (axis != null) {
            axis.setPlot(this);
            axis.addChangeListener(this);
        }

        // plot is likely registered as a listener with the existing axis...
        if (this.rangeAxis != null) {
            this.rangeAxis.removeChangeListener(this);
        }

        this.rangeAxis = axis;
        notifyListeners(new PlotChangeEvent(this));

    }

    /**
     * Sets the colorbar for the plot.
     *
     * @param axis The new axis (null permitted).
     */
    public void setColorBarAxis(ColorBar axis) {

        this.colorBar = axis;
        notifyListeners(new PlotChangeEvent(this));

    }

    /**
     * Returns the data area ratio.
     *
     * @return The ratio.
     */
    public double getDataAreaRatio() {
        return this.dataAreaRatio;
    }

    /**
     * Sets the data area ratio.
     *
     * @param ratio  the ratio.
     */
    public void setDataAreaRatio(double ratio) {
        this.dataAreaRatio = ratio;
    }

    /**
     * Adds a marker for the domain axis.
     * <P>
     * Typically a marker will be drawn by the renderer as a line perpendicular
     * to the range axis, however this is entirely up to the renderer.
     *
     * @param marker the marker.
     */
    public void addDomainMarker(Marker marker) {

        if (this.domainMarkers == null) {
            this.domainMarkers = new java.util.ArrayList();
        }
        this.domainMarkers.add(marker);
        notifyListeners(new PlotChangeEvent(this));

    }

    /**
     * Clears all the domain markers.
     */
    public void clearDomainMarkers() {
        if (this.domainMarkers != null) {
            this.domainMarkers.clear();
            notifyListeners(new PlotChangeEvent(this));
        }
    }

    /**
     * Adds a marker for the range axis.
     * <P>
     * Typically a marker will be drawn by the renderer as a line perpendicular
     * to the range axis, however this is entirely up to the renderer.
     *
     * @param marker The marker.
     */
    public void addRangeMarker(Marker marker) {

        if (this.rangeMarkers == null) {
            this.rangeMarkers = new java.util.ArrayList();
        }
        this.rangeMarkers.add(marker);
        notifyListeners(new PlotChangeEvent(this));

    }

    /**
     * Clears all the range markers.
     */
    public void clearRangeMarkers() {
        if (this.rangeMarkers != null) {
            this.rangeMarkers.clear();
            notifyListeners(new PlotChangeEvent(this));
        }
    }

    /**
     * Adds an annotation to the plot.
     *
     * @param annotation  the annotation.
     */
    public void addAnnotation(XYAnnotation annotation) {

        if (this.annotations == null) {
            this.annotations = new java.util.ArrayList();
        }
        this.annotations.add(annotation);
        notifyListeners(new PlotChangeEvent(this));

    }

    /**
     * Clears all the annotations.
     */
    public void clearAnnotations() {
        if (this.annotations != null) {
            this.annotations.clear();
            notifyListeners(new PlotChangeEvent(this));
        }
    }

    /**
     * Checks the compatibility of a domain axis, returning true if the axis is
     * compatible with the plot, and false otherwise.
     *
     * @param axis The proposed axis.
     *
     * @return <code>true</code> if the axis is compatible with the plot.
     */
    public boolean isCompatibleDomainAxis(ValueAxis axis) {

        return true;

    }

    /**
     * Draws the plot on a Java 2D graphics device (such as the screen or a 
     * printer).
     * <P>
     * The optional <code>info</code> argument collects information about the 
     * rendering of the plot (dimensions, tooltip information etc).  Just pass
     * in <code>null</code> if you do not need this information.
     *
     * @param g2  the graphics device.
     * @param area  the area within which the plot (including axis labels)
     *              should be drawn.
     * @param anchor  the anchor point (<code>null</code> permitted).
     * @param parentState  the state from the parent plot, if there is one.
     * @param info  collects chart drawing information (<code>null</code> 
     *              permitted).
     */
    public void draw(Graphics2D g2, Rectangle2D area, Point2D anchor,
                     PlotState parentState,
                     PlotRenderingInfo info) {

        // if the plot area is too small, just return...
        boolean b1 = (area.getWidth() <= MINIMUM_WIDTH_TO_DRAW);
        boolean b2 = (area.getHeight() <= MINIMUM_HEIGHT_TO_DRAW);
        if (b1 || b2) {
            return;
        }

        // record the plot area...
        if (info != null) {
            info.setPlotArea(area);
        }

        // adjust the drawing area for plot insets (if any)...
        RectangleInsets insets = getInsets();
        insets.trim(area);

        AxisSpace space = new AxisSpace();
        
        space = this.domainAxis.reserveSpace(
            g2, this, area, RectangleEdge.BOTTOM, space
        );
        space = this.rangeAxis.reserveSpace(
            g2, this, area, RectangleEdge.LEFT, space
        );

        Rectangle2D estimatedDataArea = space.shrink(area, null);
        
        AxisSpace space2 = new AxisSpace();
        space2 = this.colorBar.reserveSpace(
            g2, this, area, estimatedDataArea, this.colorBarLocation, 
            space2
        );
        Rectangle2D adjustedPlotArea = space2.shrink(area, null);
        
        Rectangle2D dataArea = space.shrink(adjustedPlotArea, null);

        Rectangle2D colorBarArea = space2.reserved(
            area, this.colorBarLocation
        );

        // additional dataArea modifications
        if (getDataAreaRatio() != 0.0) { //check whether modification is
            double ratio = getDataAreaRatio();
            Rectangle2D tmpDataArea = (Rectangle2D) dataArea.clone();
            double h = tmpDataArea.getHeight();
            double w = tmpDataArea.getWidth();

            if (ratio > 0) { // ratio represents pixels
                if (w * ratio <= h) {
                    h = ratio * w;
                }
                else {
                    w = h / ratio;
                }
            }
            else {  // ratio represents axis units
                ratio *= -1.0;
                double xLength = getDomainAxis().getRange().getLength();
                double yLength = getRangeAxis().getRange().getLength();
                double unitRatio = yLength / xLength;

                ratio = unitRatio * ratio;

                if (w * ratio <= h) {
                    h = ratio * w;
                }
                else {
                    w = h / ratio;
                }
            }

            dataArea.setRect(
                tmpDataArea.getX() + tmpDataArea.getWidth() / 2 - w / 2,
                tmpDataArea.getY(), w, h
            );
        }

        if (info != null) {
            info.setDataArea(dataArea);
        }

        CrosshairState crosshairState = new CrosshairState();
        crosshairState.setCrosshairDistance(Double.POSITIVE_INFINITY);

        // draw the plot background...
        drawBackground(g2, dataArea);

        double cursor = dataArea.getMaxY();
        if (this.domainAxis != null) {
            this.domainAxis.draw(
                g2, cursor, adjustedPlotArea, dataArea, RectangleEdge.BOTTOM, 
                info
            );
        }

        if (this.rangeAxis != null) {
            cursor = dataArea.getMinX();
            this.rangeAxis.draw(
                g2, cursor, adjustedPlotArea, dataArea, RectangleEdge.LEFT, info
            );
        }

        if (this.colorBar != null) {
            cursor = 0.0;
            cursor = this.colorBar.draw(
                g2, cursor, adjustedPlotArea, dataArea, colorBarArea, 
                this.colorBarLocation
            );
        }
        Shape originalClip = g2.getClip();
        Composite originalComposite = g2.getComposite();

        g2.clip(dataArea);
        g2.setComposite(AlphaComposite.getInstance(
            AlphaComposite.SRC_OVER, getForegroundAlpha())
        );
        render(g2, dataArea, info, crosshairState);

        if (this.domainMarkers != null) {
            Iterator iterator = this.domainMarkers.iterator();
            while (iterator.hasNext()) {
                Marker marker = (Marker) iterator.next();
                drawDomainMarker(g2, this, getDomainAxis(), marker, dataArea);
            }
        }

        if (this.rangeMarkers != null) {
            Iterator iterator = this.rangeMarkers.iterator();
            while (iterator.hasNext()) {
                Marker marker = (Marker) iterator.next();
                drawRangeMarker(g2, this, getRangeAxis(), marker, dataArea);
            }
        }

// TO DO:  these annotations only work with XYPlot, see if it is possible to 
// make ContourPlot a subclass of XYPlot (DG);

//        // draw the annotations...
//        if (this.annotations != null) {
//            Iterator iterator = this.annotations.iterator();
//            while (iterator.hasNext()) {
//                Annotation annotation = (Annotation) iterator.next();
//                if (annotation instanceof XYAnnotation) {
//                    XYAnnotation xya = (XYAnnotation) annotation;
//                    // get the annotation to draw itself...
//                    xya.draw(g2, this, dataArea, getDomainAxis(), 
//                             getRangeAxis());
//                }
//            }
//        }

        g2.setClip(originalClip);
        g2.setComposite(originalComposite);
        drawOutline(g2, dataArea);

    }

    /**
     * Draws a representation of the data within the dataArea region, using the
     * current renderer.
     * <P>
     * The <code>info</code> and <code>crosshairState</code> arguments may be 
     * <code>null</code>.
     *
     * @param g2  the graphics device.
     * @param dataArea  the region in which the data is to be drawn.
     * @param info  an optional object for collection dimension information.
     * @param crosshairState  an optional object for collecting crosshair info.
     */
    public void render(Graphics2D g2, Rectangle2D dataArea,
                       PlotRenderingInfo info, CrosshairState crosshairState) {

        // now get the data and plot it (the visual representation will depend
        // on the renderer that has been set)...
        ContourDataset data = getDataset();
        if (data != null) {

            ColorBar zAxis = getColorBar();

            if (this.clipPath != null) {
                GeneralPath clipper = getClipPath().draw(
                    g2, dataArea, this.domainAxis, this.rangeAxis
                );
                if (this.clipPath.isClip()) {
                    g2.clip(clipper);
                }
            }

            if (this.renderAsPoints) {
                pointRenderer(g2, dataArea, info, this,
                        this.domainAxis, this.rangeAxis, zAxis,
                              data, crosshairState);
            }
            else {
                contourRenderer(g2, dataArea, info, this,
                        this.domainAxis, this.rangeAxis, zAxis,
                                data, crosshairState);
            }

            // draw vertical crosshair if required...
            setDomainCrosshairValue(crosshairState.getCrosshairX(), false);
            if (isDomainCrosshairVisible()) {
                drawVerticalLine(g2, dataArea,
                                 getDomainCrosshairValue(),
                                 getDomainCrosshairStroke(),
                                 getDomainCrosshairPaint());
            }

            // draw horizontal crosshair if required...
            setRangeCrosshairValue(crosshairState.getCrosshairY(), false);
            if (isRangeCrosshairVisible()) {
                drawHorizontalLine(g2, dataArea,