code: function (d, chart, series) {
              var returnY = 0;
              if (series.y._hasTimeField()) {
                  returnY = series.y._scale(d.y) - (dimple._helpers.height(d, chart, series) / 2);
              } else if (series.y.measure !== null && series.y.measure !== undefined) {
                  returnY = series.y._scale(d.y);
              } else {
                  returnY = (series.y._scale(d.y) - (chart._heightPixels() / series.y._max)) + dimple._helpers.yGap(chart, series) + (d.yOffset * (dimple._helpers.height(d, chart, series) + 2 * dimple._helpers.yClusterGap(d, chart, series))) + dimple._helpers.yClusterGap(d, chart, series);
              }
              return returnY;
          }
docs: Calculate the top left y position for bar type charts