NumberAxis yAxis = new NumberAxis("Y");
//yAxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());
yAxis.setLowerMargin(0.0D);
yAxis.setUpperMargin(0.0D);
XYBlockRenderer renderer = new XYBlockRenderer();
PaintScale scale = new GrayPaintScale(-2D, 1.0D);
renderer.setPaintScale(scale);
XYPlot plot = new XYPlot(dataset, xAxis, yAxis, renderer);
plot.setBackgroundPaint(Color.lightGray);
plot.setDomainGridlinesVisible(false);
plot.setRangeGridlinePaint(Color.white);