if (getUseSeriesOffset()) {
                        x0 = domainAxis.getCategorySeriesMiddle(
                                dataset.getColumnKey(column - 1),
                                dataset.getRowKey(row), dataset,
                                getItemMargin(), dataArea,
                                plot.getDomainAxisEdge());
                    }
                    else {
                        x0 = domainAxis.getCategoryMiddle(column - 1,
                                getColumnCount(), dataArea,
                                plot.getDomainAxisEdge());