In this example we will develop a simple moving average indicator. Let's, create an indicator template project and start.
See examples of some strategies, integrations and indicators in our Github repository
Input parameters
First of all it is important to decide what parameters will our indicator have. We are building a simple moving average, so it will have only two parameters: Period and Price type, that will be used for calculations
#region Parameters[InputParameter("Period of Simple Moving Average", 0, 1, 999, 1, 1)]public int Period = 10;[InputParameter("Sources prices for MA", 1, variants: new object[]{ "Close", PriceType.Close, "Open", PriceType.Open, "High", PriceType.High, "Low", PriceType.Low, "Typical", PriceType.Typical, "Median", PriceType.Median, "Weighted", PriceType.Weighted})]public PriceType SourcePrice = PriceType.Close;#endregion Parameters
Ok, done let's go ahead
Indicator's general info
Our next step is to set a general indicators info, all this information you will see in Indicator's lookup, when you decide to select it. Also, here we need to define how many data series will our indicator have and should it be drawn in separate window or directly on a chart.
All these tasks we can solve in constructor function, ok great, let's do it
public SMA() : base(){ Name = "Simple Moving Average Example"; Description = "Average price for the last N periods"; ShortName = "SMA (" + Period + ":" + SourcePrice.ToString() + ")"; AddLineSeries("SMA", Color.Red, 1, LineStyle.Solid); SeparateWindow = false;}
Core logic
We will save OnInit function empty, because our indicator does not require any one-time logic that should be executed when we add indicator on a chart
protected override void OnInit(){}
All calculations will occur when we receive a new quote, to process it we need to override OnUpdate function
protected override void OnUpdate(UpdateArgs args){ if (Count <= Period) return; double sum = 0.0; for (int i = 0; i < Period; i++) sum += GetPrice(SourcePrice, i); SetValue(sum / Period);}
Pay your attention at:
if (Count <= Period) return;
Here we check is it enough historical bars to calculate one indicator's point, if yes - we continue calculation otherwise skip it.
To calculate average price we need to request price data, we can do it by calling GetPrice function
sum += GetPrice(SourcePrice, i);
Once, all calculations are done we set the result value to indicators data serie
All source code
That is all, that was easy. As a conclusion take a look at all source code
using System;using System.Drawing;using TradingPlatform.BusinessLayer;namespace MovingAverages{ public class SMA : Indicator { #region Parameters [InputParameter("Period of Simple Moving Average", 0, 1, 999, 1, 1)] public int Period = 10; [InputParameter("Sources prices for MA", 1, variants: new object[]{ "Close", PriceType.Close, "Open", PriceType.Open, "High", PriceType.High, "Low", PriceType.Low, "Typical", PriceType.Typical, "Median", PriceType.Median, "Weighted", PriceType.Weighted })] public PriceType SourcePrice = PriceType.Close; #endregion Parameters public SMA() : base() { Name = "Simple Moving Average Example"; Description = "Average price for the last N periods"; ShortName = "SMA (" + Period + ":" + SourcePrice.ToString() + ")"; AddLineSeries("SMA", Color.Red, 1, LineStyle.Solid); SeparateWindow = false; } protected override void OnInit() { } protected override void OnUpdate(UpdateArgs args) { if (Count <= Period) return; double sum = 0.0; for (int i = 0; i < Period; i++) sum += GetPrice(SourcePrice, i); SetValue(sum / Period); } }}
