KeltnerChannel

ÿþ//+------------------------------------------------------------------+

//|                                              KeltnerChannelE.mq5 |

//                                        Based on version by Gilani |

//|                                Copyright 2020, Andrei Novichkov. |

//|                                               http://fxstill.com |

//|   Telegram: https://t.me/fxstill (Literature on cryptocurrencies,| 

//|                                   development and code. )        |

//+------------------------------------------------------------------+

#property copyright "Copyright 2020, Andrei Novichkov."

#property link      "http://fxstill.com"

#property version   "1.00"



#property strict



#property description "Displays Keltner Channel technical indicator."



#property indicator_chart_window



#property indicator_buffers 3

#property indicator_plots 3



#property indicator_width1 1

#property indicator_color1 clrRed

#property indicator_type1 DRAW_LINE

#property indicator_style1 STYLE_SOLID

#property indicator_label1 "KeltnerTop"



#property indicator_width2 1

#property indicator_color2 clrOliveDrab

#property indicator_type2 DRAW_LINE

#property indicator_style2 STYLE_DASHDOT

#property indicator_label2 "KeltnerMiddle"



#property indicator_width3 1

#property indicator_color3 clrRed

#property indicator_type3 DRAW_LINE

#property indicator_style3 STYLE_SOLID

#property indicator_label3 "KeltnerBottom"



//---- input parameters

input int      MA_Period            = 10;           // Period

input double   inpMulti             = 2.0;          // Channel multiplicator

input bool     bAtr                 = false;        // Use ATR

input ENUM_MA_METHOD     Mode       = MODE_SMA;     // MA Mode

input ENUM_APPLIED_PRICE Price_Type = PRICE_TYPICAL;// Price Type



double top[], middle[], bottom[];



int myMA, atr;

static int MINBAR = MA_Period + 1;



//+------------------------------------------------------------------+

//| Custom indicator initialization function                         |

//+------------------------------------------------------------------+

int OnInit() {

   SetIndexBuffer(0,top,     INDICATOR_DATA);

   SetIndexBuffer(1,middle,  INDICATOR_DATA);

   SetIndexBuffer(2,bottom,  INDICATOR_DATA);

   

   ArraySetAsSeries(top,     true);    

   ArraySetAsSeries(middle,  true);   

   ArraySetAsSeries(bottom,  true);   

   

   IndicatorSetString(INDICATOR_SHORTNAME,"KeltnerChannel" + IntegerToString(MA_Period) );

   IndicatorSetInteger(INDICATOR_DIGITS,_Digits);



// To determine the position of the center line of the channel. 

   myMA = iMA(NULL, 0, MA_Period, 0, Mode, Price_Type);

   if (myMA == INVALID_HANDLE) {

      Print("Error while open iMA");

      return(INIT_FAILED);

   }      

// If specified in the input parameters, ATP is used to compute the upper and lower bounds.  

   if (bAtr) {

      atr = iATR(NULL, 0, MA_Period);

      if (atr == INVALID_HANDLE) {

         Print("Error while open iATR");

         return(INIT_FAILED);

      }       

   } else atr = INVALID_HANDLE;

   

   return INIT_SUCCEEDED;

}

  

void OnDeinit(const int reason) {

   IndicatorRelease(myMA);

   if (atr != INVALID_HANDLE)

      IndicatorRelease(atr);

}  



// Filling indicator buffers

void GetValue(const double& h[], const double& l[], int shift) {



   double ma[1];

   if (CopyBuffer(myMA, 0, shift, 1, ma) <= 0) return;



// Center line  

   middle[shift] = ma[0];



// Channel boundaries   

   double a = avg(h, l, shift);

   top[shift]    = middle[shift] + a * inpMulti;

   bottom[shift] = middle[shift] - a * inpMulti;   

}



// Calculate the value of the multiplier to calculate the position of the boundaries

double avg(const double& High[],const double& Low[], int shift) {

   

   double sum = 0.0;

// Averaging the size of the candlestick body for the MA_Period period  

   if (atr == INVALID_HANDLE) {

      for(int i = shift; i < shift + MA_Period; i++)

         sum += High[i] - Low[i];

         

   } else {

// We use ATR data for the same period

      double t[];

      ArrayResize(t, MA_Period);

      ArrayInitialize(t, 0);

      

      if (CopyBuffer(atr, 0, shift, MA_Period, t) <= 0) return sum;

      

      for(int i = 0; i < MA_Period; i++)

         sum += t[i];

   }

   

   return sum / MA_Period;

}



//+------------------------------------------------------------------+

//| Custom indicator iteration function                              |

//+------------------------------------------------------------------+

int OnCalculate(const int rates_total,

                const int prev_calculated,

                const datetime &time[],

                const double &open[],

                const double &high[],

                const double &low[],

                const double &close[],

                const long &tick_volume[],

                const long &volume[],

                const int &spread[]) {

// MINBAR - "non-computed" indicator tail               

      if(rates_total <= MINBAR) return 0;

      ArraySetAsSeries(close,true);    

      ArraySetAsSeries(high, true); 

      ArraySetAsSeries(low,  true); 

      int limit = rates_total - prev_calculated;

      if (limit == 0)        {   // A new tick

      } else if (limit == 1) {   // A new bar

// Calculations on the last closed candle     

         GetValue(high, low, 1);   

         return(rates_total);    

      } else if (limit > 1)  {   // The first call of the indicator, changing the timeframe, loading history

         ArrayInitialize(middle, EMPTY_VALUE);

         ArrayInitialize(top,    EMPTY_VALUE);

         ArrayInitialize(bottom, EMPTY_VALUE);

         limit = rates_total - MINBAR;

// Calculations on history        

         for(int i = limit; i >= 1 && !IsStopped(); i--)

            GetValue(high, low, i);

         return(rates_total);         

      }

// Calculations at each new tick. Perhaps this GetValue() call can be commented out. Then

// the indicator will be limited to work only on closed candles    

      GetValue(high, low, 0);       

         

   return(rates_total);

  }