Summary:
This indicator simply draws lines along lows, and then adjusts them as new lows form. This creates the lower band of the boxes that are used to normalize a trend.

Calculation:
Complex, see script.

Developer:
Nicolas Darvas

                    
#region Namespaces using System; using System.IO; using System.Linq; #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 symbol index for which to calculate the indicator script. private int _symbolIndex; // Use for holding values to mark top of box and generating next state. private double _boxTop = double.MinValue; // Use for holding values to mark bottom of box and generating next state. private double _boxBottom = double.MaxValue; // Use for holding the bar high to determinte next state. private double _currentBarHigh; // Use for holding the bar low to determinte next state. private double _currentBarLow; // Use for the state series. private const int STATE = 0; #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, String or an API Type. /// (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="symbolIndex" type="Symbol" default="">Use for the underlying symbol index for which to calculate the indicator script.</param> public void OnInitialize(int symbolIndex) { // Set the symbol index. _symbolIndex = symbolIndex; // Create the internal series required for the Darvas Box calculation. 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() { // Check whether this is the first bar. if (IndicatorValueCount() == 0) { // Get the current bar high. _currentBarHigh = BarHigh(_symbolIndex); // Get the current bar low. _currentBarLow = BarLow(_symbolIndex); // Keep the current state. IndicatorSetSeriesValue(STATE, 0, GetNextState()); // Return the bar close. return BarClose(_symbolIndex); } else { // Update and keep the current state between bars. IndicatorSetSeriesValue(STATE, 0, IndicatorGetSeriesValue(STATE, 1)); // Get the bar high. _currentBarHigh = BarHigh(_symbolIndex); // Get the bar low. _currentBarLow = BarLow(_symbolIndex); // Check whether a buy or sell signal should be generated. if ((IndicatorGetSeriesValue(STATE, 0) == 5 && _currentBarHigh > _boxTop) || (IndicatorGetSeriesValue(STATE, 0) == 5 && _currentBarLow < _boxBottom)) // Reset state back to 0. IndicatorSetSeriesValue(STATE, 0, 0); // Update the state to the next state. IndicatorSetSeriesValue(STATE, 0, GetNextState()); } // Check whether the bottom box value hasn't yet been set. if (_boxBottom == double.MaxValue) // Return the bar close. return BarClose(_symbolIndex); else // Return the bottom box value. return _boxBottom; } #endregion #region GetNextState /// <summary> /// Use to get the next indicator state. /// </summary> /// <returns>The next indicator state.</returns> private int GetNextState() { // Determine how to update the box top and box bottom values. switch ((int) IndicatorGetSeriesValue(STATE, 0)) { case 0: // Initalized or buy/sell triggered, move to state 1. _boxTop = _currentBarHigh; _boxBottom = double.MaxValue; return 1; case 1: // Check whether the high price is lower then upper band level, move to state 2. if (_boxTop > _currentBarHigh) return 2; else { _boxTop = _currentBarHigh; // Set the upper band to current bar high. return 1; } case 2: // Check whether the high price is lower then upper band level, move to state 3. if (_boxTop > _currentBarHigh) { _boxBottom = _currentBarLow; // Set the lower band level to current bar low. return 3; } else { // Else go to state 1. _boxTop = _currentBarHigh; return 1; } case 3: // Check whether the high price is lower than the upper band level and low price is greater than the lower band level, move to state 4. if (_boxTop > _currentBarHigh) { if (_boxBottom < _currentBarLow) return 4; else { // Else set lower band level to current bar low. _boxBottom = _currentBarLow; return 3; } } else { // Check whether the high price is not lower than upper band level, move to state 1. _boxTop = _currentBarHigh; _boxBottom = double.MaxValue; return 1; } case 4: // Check whether the high price is lower than upper band level and low price is greater then lower band level, move to state 5. if (_boxTop > _currentBarHigh) { if (_boxBottom < _currentBarLow) return 5; else { // Else move to state 3. _boxBottom = _currentBarLow; return 3; } } else { // Check whether the high price is greater than or equal to upper band move to state 1. _boxTop = _currentBarHigh; _boxBottom = double.MaxValue; return 1; } case 5: // Check whether in state 5 stay in state 5 until buy/sell triggers and resets state. return 5; default: return (int) IndicatorGetSeriesValue(STATE, 0); } } #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.DARK_ORANGE, 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() { // OnSelectPen Content return 0; } #endregion } }

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