double linkX = plotArea.getX() + gapHorizontal / 2;
        double linkY = plotArea.getY() + gapVertical / 2;
        double linkW = plotArea.getWidth() - gapHorizontal;
        double linkH = plotArea.getHeight() - gapVertical;
        
        // make the link area a square if the pie chart is to be circular...
        if (isCircular()) { // is circular?
            double min = Math.min(linkW, linkH) / 2;
            linkX = (linkX + linkX + linkW) / 2 - min;
            linkY = (linkY + linkY + linkH) / 2 - min;
            linkW = 2 * min;
            linkH = 2 * min;