Par_MA

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

//|                                                       Par_MA.mq5 |

//|                        Copyright 2018, MetaQuotes Software Corp. |

//|                                                 https://mql5.com |

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

#property copyright "Copyright 2018, MetaQuotes Software Corp."

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

#property version   "1.00"

#property description "Parabolic Moving Average indicator"

#property indicator_chart_window

#property indicator_buffers 2

#property indicator_plots   1

//--- plot MA

#property indicator_label1  "Parabolic MA"

#property indicator_type1   DRAW_LINE

#property indicator_color1  clrDodgerBlue

#property indicator_style1  STYLE_SOLID

#property indicator_width1  1

//--- input parameters

input uint                 InpPeriod         =  20;            // Period

input ENUM_APPLIED_PRICE   InpAppliedPrice   =  PRICE_CLOSE;   // Applied price

//--- indicator buffers

double         BufferPMA[];

double         BufferMA[];

//--- global variables

double         sum_x;

double         sum_x2;

double         sum_x3;

double         sum_x4;

int            period_pma;

int            handle_ma;

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

//| Custom indicator initialization function                         |

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

int OnInit()

  {

//--- set global variables

   period_pma=int(InpPeriod<3 ? 3 : InpPeriod);

   sum_x=(1.0+period_pma)*period_pma/2.0;

   sum_x2=(1.0+period_pma)*(2.0*period_pma+1.0)*period_pma/6.0;

   sum_x3=sum_x*sum_x;

   sum_x4=(1.0+period_pma)*period_pma*(2.0*period_pma+1.0)*(3.0*period_pma*period_pma+3.0*period_pma-1.0)/30.0;

//--- indicator buffers mapping

   SetIndexBuffer(0,BufferPMA,INDICATOR_DATA);

   SetIndexBuffer(1,BufferMA,INDICATOR_CALCULATIONS);

//--- setting indicator parameters

   IndicatorSetString(INDICATOR_SHORTNAME,"Parabolic MA ("+(string)period_pma+")");

   IndicatorSetInteger(INDICATOR_DIGITS,Digits());

//--- setting buffer arrays as timeseries

   ArraySetAsSeries(BufferPMA,true);

   ArraySetAsSeries(BufferMA,true);

//--- create MA's handles

   ResetLastError();

   handle_ma=iMA(NULL,PERIOD_CURRENT,1,0,MODE_SMA,InpAppliedPrice);

   if(handle_ma==INVALID_HANDLE)

     {

      Print("The iMA(1) object was not created: Error ",GetLastError());

      return INIT_FAILED;

     }

//---

   return(INIT_SUCCEEDED);

  }

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

//| 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[])

  {

//--- @>25@:0 8 @0AGQB :>;8G5AB20 ?@>AG8BK205<KE 10@>2

   if(rates_total<fmax(period_pma,4)) return 0;

//--- @>25@:0 8 @0AGQB :>;8G5AB20 ?@>AG8BK205<KE 10@>2

   int limit=rates_total-prev_calculated;

   if(limit>1)

     {

      limit=rates_total-period_pma-1;

      ArrayInitialize(BufferPMA,EMPTY_VALUE);

      ArrayInitialize(BufferMA,0);

     }

//--- >43>B>2:0 40==KE

   int count=(limit>1 ? rates_total : 1),copied=0;

   copied=CopyBuffer(handle_ma,0,0,count,BufferMA);

   if(copied!=count) return 0;

   

//---  0AGQB 8=48:0B>@0

   for(int i=limit; i>=0 && !IsStopped(); i--)

     {

      double sum_y=0.0;

      double sum_xy=0.0;

      double sum_x2y=0.0;

      for(int j=1;j<=period_pma;j++)

        {

         double tmp=BufferMA[i+period_pma-j];

         sum_y+=tmp;

         sum_xy+=tmp*j;

         sum_x2y+=tmp*j*j;

        }

      double F=sum_x3;

      double M=sum_x4;

      double P=sum_y;

      double R=sum_xy;

      double S=sum_x2y;

      double E=sum_x2;

      double L=sum_x3;

      double Q=sum_x/period_pma;

      E-=Q*sum_x;

      F-=Q*sum_x2;

      R-=Q*P;

      Q=sum_x2/period_pma;

      L-=Q*sum_x;

      M-=Q*sum_x2;

      S-=Q*P;

      Q=L/E;

      double B2=(S-R*Q)/(M-F*Q);

      double B1=(R-F*B2)/E;

      double B0=(P-sum_x*B1-sum_x2*B2)/period_pma;

      BufferPMA[i]=B0+(B1+B2*period_pma)*period_pma;

     }



//--- return value of prev_calculated for next call

   return(rates_total);

  }

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