public class ErrorExample {

	public static void main(String[] args) {
		final Shell shell = new Shell();
		shell.setSize(300, 250);
	    shell.open();
	    
	    //use LightweightSystem to create the bridge between SWT and draw2D
		final LightweightSystem lws = new LightweightSystem(shell);
		
		//create a new XY Graph.
		XYGraph xyGraph = new XYGraph();
		xyGraph.setTitle("Error Example");
		xyGraph.primaryYAxis.setTitle("Y - axis");
		xyGraph.primaryXAxis.setTitle("X - axis");
		xyGraph.primaryYAxis.setAutoScale(false);
		xyGraph.primaryXAxis.setAutoScale(false);
		xyGraph.primaryXAxis.setShowMajorGrid(true);
		xyGraph.primaryYAxis.setShowMajorGrid(true);
		xyGraph.primaryXAxis.setRange(new Range(0.0,5.0));
		xyGraph.primaryYAxis.setRange(new Range(0.0,10.0));
		//set it as the content of LightwightSystem
		lws.setContents(xyGraph);
		
		//create a trace data provider, which will provide the data to the trace.
		CircularBufferDataProvider traceDataProvider = new CircularBufferDataProvider(false);
		traceDataProvider.setBufferSize(100);	
		traceDataProvider.addSample(new Sample(-1, 11));
		traceDataProvider.addSample(new Sample(6,4));
		
		//create the trace
		Trace trace = new Trace("Trace1-XY Plot", 
				xyGraph.primaryXAxis, xyGraph.primaryYAxis, traceDataProvider);
		
		//set trace property
		trace.setPointStyle(PointStyle.XCROSS);

		//add the trace to xyGraph
		xyGraph.addTrace(trace);
					
	   
	    Display display = Display.getDefault();
	    while (!shell.isDisposed()) {
	      if (!display.readAndDispatch())
	        display.sleep();
	    }
	   
	}

}

private ISample[] getStraightLineIntersection(final ISample dp1,
			final ISample dp2) {
		final double x1 = dp1.getXValue();
		final double y1 = dp1.getYValue();
		final double x2 = dp2.getXValue();
		final double y2 = dp2.getYValue();
		final double dx = x2 - x1;
		final double dy = y2 - y1;
		final ISample[] dpTuple = new Sample[2];
		int count = 0; // number of valid dbTuple entries
		double x, y;

		if (dy != 0.0) { // Intersection with lower xAxis
			final double ymin = yAxis.getRange().getLower();
			x = (ymin - y1) * dx / dy + x1;
			y = ymin;
			if (evalDP(x, y, dp1, dp2))
				dpTuple[count++] = new Sample(x, y);
			// Intersection with upper xAxis
			final double ymax = yAxis.getRange().getUpper();
			x = (ymax - y1) * dx / dy + x1;
			y = ymax;
			if (evalDP(x, y, dp1, dp2))
				dpTuple[count++] = new Sample(x, y);
		}
		// A line that runs diagonally through the plot,
		// hitting for example the lower left as well as upper right corners
		// would cut both X as well as both Y axes.
		// Return only the X axes hits, since Y axes hits are actually the
		// same points.
		if (count == 2)
			return dpTuple;
		if (dx != 0.0) { // Intersection with left yAxis
			final double xmin = xAxis.getRange().getLower();
			x = xmin;
			y = (xmin - x1) * dy / dx + y1;
			if (evalDP(x, y, dp1, dp2))
				dpTuple[count++] = new Sample(x, y);
			// Intersection with right yAxis
			final double xmax = xAxis.getRange().getUpper();
			x = xmax;
			y = (xmax - x1) * dy / dx + y1;
			if (dx != 0 && evalDP(x, y, dp1, dp2))
				dpTuple[count++] = new Sample(x, y);
		}
		return dpTuple;
	}