Relative Moving Average

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

//|                                          Mage Moving Average-RMA |

//|                                  Copyright 2023, MetaQuotes Ltd. |

//|                                             https://www.mql5.com |

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

#property copyright "Copyright 2023, Mage"

#property link      "https://www.mql5.com"

#property version   "1.00"

#property indicator_chart_window

#property indicator_buffers 1

#property indicator_plots   1

//--- plot Slow Speed Line

#property indicator_label1  "RMA"

#property indicator_type1   DRAW_LINE

#property indicator_color1  clrRed

#property indicator_style1  STYLE_SOLID

#property indicator_width1  1

//--- input parameters

input int InpPeriod   =12;   //RMA Period



//--- indicator buffers

double    buffer_m[];



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

//| Custom indicator initialization function                         |

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

int OnInit()

  {

//--- indicator buffers mapping

   SetIndexBuffer(0,buffer_m,INDICATOR_DATA);

//--- set Digits

   IndicatorSetInteger(INDICATOR_DIGITS,_Digits+1);

//---name

   IndicatorSetString(INDICATOR_SHORTNAME,"Mage_RMA"+string(InpPeriod));

//--- set first bar from what index will be drawn

   PlotIndexSetInteger(0,PLOT_DRAW_BEGIN,InpPeriod);

//---

   return(INIT_SUCCEEDED);

  }



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

//| Custom indicator iteration function                              |

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

int OnCalculate(const int rates_total,

                const int prev_calculated,

                const int begin,

                const double& price[])

  {

   ExponentialMAOnBuffer(rates_total,prev_calculated,0,InpPeriod,price,buffer_m);

   return(rates_total);

  }

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

//| Calculation Buffer                                               |

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

int ExponentialMAOnBuffer(const int rates_total,const int prev_calculated,const int begin,const int period,const double& price[],double& buffer[])

  {

//--- check period

   if(period<=1 || period>(rates_total-begin))

      return(0);

//--- save and clear 'as_series' flags

   bool as_series_price=ArrayGetAsSeries(price);

   bool as_series_buffer=ArrayGetAsSeries(buffer);



   ArraySetAsSeries(price,false);

   ArraySetAsSeries(buffer,false);

//--- calculate start position

   int    start_position;

   double smooth_factor=1.0/period;



   if(prev_calculated==0)  // first calculation or number of bars was changed

     {

      //--- set empty value for first bars

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

         buffer[i]=0.0;

      //--- calculate first visible value

      start_position=period+begin;

      buffer[begin] =price[begin];



      for(int i=begin+1; i<start_position; i++)

         buffer[i]=price[i]*smooth_factor+buffer[i-1]*(1.0-smooth_factor);

     }

   else

      start_position=prev_calculated-1;

//--- main loop

   for(int i=start_position; i<rates_total; i++)

      buffer[i]=price[i]*smooth_factor+buffer[i-1]*(1.0-smooth_factor);

//--- restore as_series flags

   ArraySetAsSeries(price,as_series_price);

   ArraySetAsSeries(buffer,as_series_buffer);

//---

   return(rates_total);

  }

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