求助 布林轨开始部分没有显示 如何解决

[niepan.syl]

你好 MT5自带的布林轨在月线中 比如黄金现货 历史数据的最开始的25根K线是没有布林轨的值的 或者说没有布林轨覆盖的 这是为什么 如何能够让最初的那些K线也有画出布林轨 谢谢

下面附上布林轨公式 参数设置是26 2 附上布林轨不显示部分的截图

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

//|                                                           BB.mq5 |

//|                   Copyright 2009-2017, MetaQuotes Software Corp. |

//|                                              http://www.mql5.com |

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

#property copyright   "2009-2017, MetaQuotes Software Corp."

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

#property description "Bollinger Bands"

#include <MovingAverages.mqh>

//---

#property indicator_chart_window

#property indicator_buffers 4

#property indicator_plots   3

#property indicator_type1   DRAW_LINE

#property indicator_color1  LightSeaGreen

#property indicator_type2   DRAW_LINE

#property indicator_color2  LightSeaGreen

#property indicator_type3   DRAW_LINE

#property indicator_color3  LightSeaGreen

#property indicator_label1  "Bands middle"

#property indicator_label2  "Bands upper"

#property indicator_label3  "Bands lower"

//--- input parametrs

input int     InpBandsPeriod=26;       // Period

input int     InpBandsShift=0;         // Shift

input double  InpBandsDeviations=2.0;  // Deviation

//--- global variables

int           ExtBandsPeriod,ExtBandsShift;

double        ExtBandsDeviations;

int           ExtPlotBegin=0;

//---- indicator buffer

double        ExtMLBuffer[];

double        ExtTLBuffer[];

double        ExtBLBuffer[];

double        ExtStdDevBuffer[];

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

//| Custom indicator initialization function                         |

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

void OnInit()

  {

//--- check for input values

   if(InpBandsPeriod<2)

     {

      ExtBandsPeriod=20;

      printf("Incorrect value for input variable InpBandsPeriod=%d. Indicator will use value=%d for calculations.",InpBandsPeriod,ExtBandsPeriod);

     }

   else ExtBandsPeriod=InpBandsPeriod;

   if(InpBandsShift<0)

     {

      ExtBandsShift=0;

      printf("Incorrect value for input variable InpBandsShift=%d. Indicator will use value=%d for calculations.",InpBandsShift,ExtBandsShift);

     }

   else

      ExtBandsShift=InpBandsShift;

   if(InpBandsDeviations==0.0)

     {

      ExtBandsDeviations=2.0;

      printf("Incorrect value for input variable InpBandsDeviations=%f. Indicator will use value=%f for calculations.",InpBandsDeviations,ExtBandsDeviations);

     }

   else ExtBandsDeviations=InpBandsDeviations;

//--- define buffers

   SetIndexBuffer(0,ExtMLBuffer);

   SetIndexBuffer(1,ExtTLBuffer);

   SetIndexBuffer(2,ExtBLBuffer);

   SetIndexBuffer(3,ExtStdDevBuffer,INDICATOR_CALCULATIONS);

//--- set index labels

   PlotIndexSetString(0,PLOT_LABEL,"Bands("+string(ExtBandsPeriod)+") Middle");

   PlotIndexSetString(1,PLOT_LABEL,"Bands("+string(ExtBandsPeriod)+") Upper");

   PlotIndexSetString(2,PLOT_LABEL,"Bands("+string(ExtBandsPeriod)+") Lower");

//--- indicator name

   IndicatorSetString(INDICATOR_SHORTNAME,"Bollinger Bands");

//--- indexes draw begin settings

   ExtPlotBegin=ExtBandsPeriod-1;

   PlotIndexSetInteger(0,PLOT_DRAW_BEGIN,ExtBandsPeriod);

   PlotIndexSetInteger(1,PLOT_DRAW_BEGIN,ExtBandsPeriod);

   PlotIndexSetInteger(2,PLOT_DRAW_BEGIN,ExtBandsPeriod);

//--- indexes shift settings

   PlotIndexSetInteger(0,PLOT_SHIFT,ExtBandsShift);

   PlotIndexSetInteger(1,PLOT_SHIFT,ExtBandsShift);

   PlotIndexSetInteger(2,PLOT_SHIFT,ExtBandsShift);

//--- number of digits of indicator value

   IndicatorSetInteger(INDICATOR_DIGITS,_Digits+1);

//---- OnInit done

  }

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

//| Custom indicator iteration function                              |

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

int OnCalculate(const int rates_total,

                const int prev_calculated,

                const int begin,

                const double &price[])

  {

//--- variables

   int pos;

//--- indexes draw begin settings, when we've recieved previous begin

   if(ExtPlotBegin!=ExtBandsPeriod+begin)

     {

      ExtPlotBegin=ExtBandsPeriod+begin;

      PlotIndexSetInteger(0,PLOT_DRAW_BEGIN,ExtPlotBegin);

      PlotIndexSetInteger(1,PLOT_DRAW_BEGIN,ExtPlotBegin);

      PlotIndexSetInteger(2,PLOT_DRAW_BEGIN,ExtPlotBegin);

     }

//--- check for bars count

   if(rates_total<ExtPlotBegin)

      return(0);

//--- starting calculation

   if(prev_calculated>1) pos=prev_calculated-1;

   else pos=0;

//--- main cycle

   for(int i=pos;i<rates_total && !IsStopped();i++)

     {

      //--- middle line

      ExtMLBuffer[i]=SimpleMA(i,ExtBandsPeriod,price);

      //--- calculate and write down StdDev

      ExtStdDevBuffer[i]=StdDev_Func(i,price,ExtMLBuffer,ExtBandsPeriod);

      //--- upper line

      ExtTLBuffer[i]=ExtMLBuffer[i]+ExtBandsDeviations*ExtStdDevBuffer[i];

      //--- lower line

      ExtBLBuffer[i]=ExtMLBuffer[i]-ExtBandsDeviations*ExtStdDevBuffer[i];

      //---

     }

//---- OnCalculate done. Return new prev_calculated.

   return(rates_total);

  }

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

//| Calculate Standard Deviation                                     |

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

double StdDev_Func(int position,const double &price[],const double &MAprice[],int period)

  {

//--- variables

   double StdDev_dTmp=0.0;

//--- check for position

   if(position<period) return(StdDev_dTmp);

//--- calcualte StdDev

   for(int i=0;i<period;i++) StdDev_dTmp+=MathPow(price[position-i]-MAprice[position],2);

   StdDev_dTmp=MathSqrt(StdDev_dTmp/period);

//--- return calculated value

   return(StdDev_dTmp);

  }

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

[Ziheng Zhuang]

历史数据最左边的部分没有显示很正常。。。这涉及到均线算法的问题，。。。本来就不应该显示。

[niepan.syl]

Ziheng Zhuang:

历史数据最左边的部分没有显示很正常。。。这涉及到均线算法的问题，。。。本来就不应该显示。

好的 谢谢