Summary:
This indicator script is a range oscillator which provides clear, timely turning points.

Calculation:
Complex, see script.

Developer:
John Ehlers

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.

                    
#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. private Indicator _indicator; // Use for the number of periods to include in the indicator script calculation. private int _periods; #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.</param> /// <param name="periods" type="Integer" default="10" 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; // Create a single internal series, since there is only one temporary variable to hold. IndicatorCreateSeries(1); } #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() { // Use for the previous FISH value. double prevFISH = 0; // Check whether this is the first item in the indicator. if (IndicatorValueCount() == 0) { // Set the prev FISH value. prevFISH = 0; // Set the required temp value. IndicatorSetSeriesValue(0, 0, 0); } else { // Keep the prev FISH value. prevFISH = this[0]; } // Use for the minimum low. double minLow = double.MaxValue; // Use for the maximum high. double maxHigh = 0; // Iterate over the indicator values in the specified period. for (int i = 0; i < _periods; i++) { // Check whether the minimum low can be improved. if (_indicator[i] < minLow) // Keep the minimum low. minLow = _indicator[i]; // Check whether the maximum high can be improved. if (_indicator[i] > maxHigh) // Keep the maximum high. maxHigh = _indicator[i]; } // Calculate the range. double range = maxHigh - minLow; // Check whether the range is invalid. if (double.IsNaN(range) || range == 0) { // Reset the range range = 0.001; } // Calculate the current value by using the previous temporary value of the previous bar. double currentValue = 0; // Check whether this is the first item in the indicator. if (IndicatorValueCount() == 0) currentValue = 0.66 * ((_indicator[0] - minLow) / range - 0.5) + 0.67; else currentValue = 0.66 * ((_indicator[0] - minLow) / range - 0.5) + 0.67 * IndicatorGetSeriesValue(0, 1); // Check whether the current value needs to be fixed. if (currentValue > 0.99) currentValue = 0.999; // Check whether the current value needs to be fixed. if (currentValue < - 0.99) currentValue = - 0.999; // Keep the temporary value for the current bar. IndicatorSetSeriesValue(0, 0, currentValue); // Calculate the fish value. return 0.5 * Math.Log((1 + currentValue) / (1 - currentValue)) + 0.5 * prevFISH; } #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", IQ_Color.NAVY, IQ_DashStyle.SOLID, 2); // Set the indicator in a new chart panel. IndicatorChartSetNewPanel(true); } #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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