Summary:
This indicator script is an oscillator which measures the size of a symbol's recent gains to the size of its recent losses and produces a number.

Range:
0 To 100

Calculation:
Complex, see script.

Developer:
J. Welles Wilder

Interpretation:
1. Overbought: When the underlying indicator is moving upwards, but the indicator script is approaching its upper bound, the underlying indicator is likely to reverse direction and move downwards.
2. Oversold: When the underlying indicator is moving downwards, but the indicator script is approaching its lower bound, the underlying indicator is likely to reverse direction and move upwards.
3. Positive Divergence: When the underlying indicator is moving downwards, but the indicator script is moving upwards, the underlying indicator is likely to reverse direction and move upwards.
4. Negative Divergence: When the underlying indicator is moving upwards, but the indicator script is moving downwards, the underlying indicator is likely to reverse direction and move downwards.

                    
#region Namespaces using System; #endregion namespace ScriptCode { /// <summary> /// Indicator scripts are used for calculating a series of numerical values. /// /// This script can be used in several ways: /// (1) It can be used on a chart. /// (2) It can be used from another script. /// (3) It can be used as a script column in a watchlist. /// </summary> public partial class MyIndicator : IndicatorScriptBase // NEVER CHANGE THE CLASS NAME { #region Variables // Use for the underlying indicator on which to calculate the indicator script. private Indicator _indicator; // Use for the number of periods to include in the indicator script calculation. private int _periods; // Use for the average gains. private double _averageGains; // Use for the average losses. private double _averageLosses; #endregion #region OnInitialize /// <summary> /// This function accepts the user parameters for the script and is called when a new indicator instance is created. /// One of the parameters accepted by it must be that of a symbol or another script that is /// based on a symbol (drawing, indicator, pattern or signal). This symbol will be used as the underlying symbol for the indicator. /// /// The parameter values can be specified from the user interface (UI) or from another script, depending on usage. /// </summary> /// -------------------------------------------------------------------------------------------------- /// PLEASE USE THE SCRIPT WIZARD (CTRL+W) TO ADD, EDIT AND REMOVE THE SCRIPT PARAMETERS /// -------------------------------------------------------------------------------------------------- /// YOU MUST SET A PARAM TAG FOR EACH PARAMETER ACCEPTED BY THIS FUNCTION. /// ALL PARAM TAGS SHOULD BE SET IN THE 'OnInitialize' REGION, RIGHT ABOVE THE 'OnInitialize' FUNCTION. /// THE ORDER OF THE TAGS MUST MATCH THE ORDER OF THE ACTUAL PARAMETERS. /// REQUIRED ATTRIBUTES: /// (1) name: The exact parameter name. /// (2) type: The type of data to collect from the user: /// Set to "Integer" when the data type is 'int' /// Set to "IntegerArray" when the data type is 'int[]' /// Set to "DateTime" when the data type is 'long' /// Set to "DateTimeArray" when the data type is 'long[]' /// Set to "Boolean" when the data type is 'bool' /// Set to "BooleanArray" when the data type is 'bool[]' /// Set to "Double" when the data type is 'double' /// Set to "DoubleArray" when the data type is 'double[]' /// Set to "String" when the data type is 'string' /// Set to "StringArray" when the data type is 'string[]' /// Set to "Indicator" when the data type is 'Indicator' /// Set to "Pattern" when the data type is 'Pattern' /// Set to "Signal" when the data type is 'Signal' /// Set to "Drawing" when the data type is 'Drawing' /// Set to "Symbol" when the data type is 'int' representing a symbol index. /// OPTIONAL ATTRIBUTES: /// (3) default: The default parameter value is only valid when the type is Integer, Boolean, Double or String. /// (4) min: The minimum parameter value is only valid when the type is Integer or Double. /// (5) max: The maximum parameter value is only valid when the type is Integer or Double. /// EXAMPLE: <param name="" type="" default="" min="" max="">Enter the parameter description here.</param> /// -------------------------------------------------------------------------------------------------- /// <param name="indicator" type="Indicator">Use for the underlying indicator on which to calculate the indicator script.</param> /// <param name="periods" type="Integer" default="14" min="1">Use for the number of periods to include in the indicator script calculation.</param> public void OnInitialize( Indicator indicator, int periods) { // Set the indicator. _indicator = indicator; // Set the number of periods. _periods = periods; // Initialize the average gains. _averageGains = double.NaN; // Initialize the average losses. _averageLosses = double.NaN; // Create internal series. IndicatorCreateSeries(2); } #endregion #region OnBarUpdate /// <summary> /// This function is used for calculating the indicator value for the latest bar (see the Indicator functions). /// </summary> /// <returns>The indicator value for the latest bar.</returns> public override double OnBarUpdate() { // Check whether there aren't enough indicator values. if (IndicatorValueCount() < _periods) return 0; // Check whether the average gains have never been initialized. if (IndicatorValueCount() == _periods) { double gain = 0; double loss = 0; // Iterate over the values. for (int i = _periods - 1; i >= 0; i--) { // Calculate the gain. gain += Math.Max(_indicator[i] - _indicator[i + 1], 0); // Calculate the loss. loss += Math.Max(_indicator[i + 1] - _indicator[i], 0); } // Initialize the gains with the SMA over the first values. _averageGains = gain / _periods; // Initialize the losses with the SMA over the first values. _averageLosses = loss / _periods; } else { // Get the last average gains value. _averageGains = IndicatorGetSeriesValue(0, 1); // Get the last average loss value. _averageLosses = IndicatorGetSeriesValue(1, 1); // Calculate the current strength. double loss = Math.Max(_indicator[1] - _indicator[0], 0); // Calculate the average loss. _averageLosses = ((_averageLosses * (_periods - 1)) + loss) / _periods; // Calculate the current strength. double gain = Math.Max(_indicator[0] - _indicator[1], 0); // Calculate the average gain. _averageGains = ((_averageGains * (_periods - 1)) + gain) / _periods; } // Keep the average gains. IndicatorSetSeriesValue(0, 0, _averageGains); // Keep the average losses. IndicatorSetSeriesValue(1, 0, _averageLosses); // Calculate the RSI. return _averageLosses == 0 ? 100 : 100 - (100 / (1 + (_averageGains / _averageLosses))); } #endregion #region OnChartSetup /// <summary> /// This function is used for setting up the indicator on the chart and registering its pens (see the IndicatorRegisterPen function). /// </summary> public override void OnChartSetup() { // Register a pen. IndicatorRegisterPen(0, "Pen", new byte[] { 150, 150, 150, 200 }, IQ_DashStyle.SOLID, 2); // Set the indicator in a new chart panel. IndicatorChartSetNewPanel(true); // Set the plot style. IndicatorChartSetPlotStyle(IQ_PlotStyle.SQUARE); // Set the indicator range. IndicatorChartSetRange(0, 100); // Set the overbought range. IndicatorChartSetColorZone(70, 70, new byte[] { 175, 25, 25, 200 }, new byte[] { 175, 25, 25, 200 }, new byte[] { 175, 25, 25, 200 }, IQ_DashStyle.SOLID, 2); // Set the oversold range. IndicatorChartSetColorZone(30, 30, new byte[] { 25, 200, 25, 200 }, new byte[] { 25, 200, 25, 200 }, new byte[] { 25, 200, 25, 200 }, IQ_DashStyle.SOLID, 2); } #endregion #region OnSelectPen /// <summary> /// This function is used for selecting a registered indicator pen with which to color the latest indicator value. /// Call the IndicatorRegisterPen function from the OnChartSetup function in order to register an indicator pen. /// </summary> /// <returns>The indicator pen index to use for coloring the latest indicator value.</returns> public override byte OnSelectPen() { // Color the indicator value with the zero pen. return 0; } #endregion } }

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