Allowed for negative bar charts

lib/DOMutil.js

@@ -160,12 +160,16 @@ exports.drawPoint = function(x, y, group, JSONcontainer, svgContainer) {
  * @param className
  */
 exports.drawBar = function (x, y, width, height, className, JSONcontainer, svgContainer) {
-//  if (height != 0) {
+  if (height != 0) {
+    if (height < 0) {
+      height *= -1;
+      y -= height;
+    }
     var rect = exports.getSVGElement('rect',JSONcontainer, svgContainer);
     rect.setAttributeNS(null, "x", x - 0.5 * width);
     rect.setAttributeNS(null, "y", y);
     rect.setAttributeNS(null, "width", width);
     rect.setAttributeNS(null, "height", height);
     rect.setAttributeNS(null, "class", className);
-//  }
+  }
 };