private DataSource createDataSource() {
			DataSource ds = new DataSource(dataPoint == 0 ? 200 : dataPoint * 2);
			ds.setVariableValue("x", 0);
			ds.setExpression(expression);
			ds.setHideHotSpot(true);
			if ((argb | ARGB_NOT_SET) != ARGB_NOT_SET) {
				ds.setColor(new Color(argb));
				argb = ARGB_NOT_SET;
			}
			if (weight > 0) {
				ds.setLineWeight(weight);
				weight = -1;
			}
			if (style > 0) {
				ds.setStroke(StrokeFactory.changeStyle(ds.getStroke(), LineStyle.getDashArray(style)));
				style = -1;
			}
			dataPoint = 0;
			return ds;
		}