Indicators | How to Plot a Discontinuous Indicator

Modified on 2008/06/14 10:37 by Eugene — Categorized as: Knowledge Base

A DataSeries is the basic data structure that represents a historical series. One of their key characteristics is that all DataSeries contain the same number of values as bars in the chart (when synchronized).

However, sometimes there can be a need to plot discontinuous indicators where certain timestamps do not have a value associated with the Y coordinate.

With Wealth-Lab .NET you can do it, here's a code snippet.


using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using WealthLab;
using WealthLab.Indicators;

namespace WealthLab.Strategies
{
	public class MyStrategy : WealthScript
	{
		protected override void Execute()
		{
			// Color Bars of the indicator based on oversold/overbought levels
			DataSeries rsi = RSI.Series( Close, 14 );
			ChartPane rsiPane = CreatePane( 60, true, true );
			PlotSeries( rsiPane, rsi, Color.Gray, WealthLab.LineStyle.Solid, 2 );
			
			for(int bar = 50; bar < Bars.Count; bar++)
			{
				if ( rsi[bar] > 70 ) SetSeriesBarColor( bar, rsi, Color.Red ); else 
				if ( rsi[bar] < 30 ) SetSeriesBarColor( bar, rsi, Color.Blue ); else
					SetSeriesBarColor( bar, rsi, Color.Transparent );
			}
		}
	}
}

Notice the setting of bar series color to Color.Transparent. What we did was simply hiding a null value from being plotted - leaving white space on the chart instead.