Please Help: I modified MT4's DMI+ADX indicator but one line is not displayed

[yyk03]

Hi everyone

I modified MT4's official DMI+ADX indicator(https://www.mql5.com/en/code/7955) to make it same as other other platforms.

The change is, MT4 calculates the EMA of (±DM/TrueRange) for ±DI while my version is to calculate EMA of ±DM and TrueRange separately then divide them. The ADX part is untouched.

- MT4's original version: ±DI = 100 * EMA(±DM/TrueRange)

- My version: ±DI = 100 * EMA(±DM) / EMA(TrueRange)

Well the ±DI part went well and displayed correctly in MT4.

However, the problem is the ADX line somehow disappeared mysteriously. Related code is even not changed! I tried a lot but still can't figure out what's happening. Can anyone help to find out the reason?

Thank you very much.

//+------------------------------------------------------------------+
//|                                                          ADX.mq4 |
//|                      Copyright © 2004, MetaQuotes Software Corp. |
//|                                       http://www.metaquotes.net/ |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2004, MetaQuotes Software Corp."
#property link      "http://www.metaquotes.net/"

#property indicator_separate_window
#property indicator_buffers 3 //Plot
#property indicator_color1 Olive
#property indicator_color2 MediumSeaGreen
#property indicator_color3 Crimson


//---- input parameters
extern int ADXPeriod=20;
//---- buffers
double ADXBuffer[];
double PlusDiBuffer[];
double MinusDiBuffer[];

double PdmBuffer[];
double MdmBuffer[];
double TrBuffer[];
double TempBuffer[];

//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {
//---- Some additional buffers are used for counting.
   IndicatorBuffers(11);
//---- indicator buffers
   SetIndexBuffer(0,ADXBuffer);
   SetIndexBuffer(1,PlusDiBuffer);
   SetIndexBuffer(2,MinusDiBuffer);
   SetIndexBuffer(5,PdmBuffer);
   SetIndexBuffer(6,MdmBuffer);
   SetIndexBuffer(7,TrBuffer);
   SetIndexBuffer(8,TempBuffer);
//---- name for DataWindow and indicator subwindow label
   IndicatorShortName("ADX("+ADXPeriod+")");
   SetIndexLabel(0,"ADX");
   SetIndexLabel(1,"+DI");
   SetIndexLabel(2,"-DI");
   
//----
   SetIndexDrawBegin(0,ADXPeriod);
   SetIndexDrawBegin(1,ADXPeriod);
   SetIndexDrawBegin(2,ADXPeriod);
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| Average Directional Movement Index                               |
//+------------------------------------------------------------------+
int start()
  {
   double pdm,mdm,tr;
   double price_high,price_low;
   int    starti,i,counted_bars=IndicatorCounted();
//----
   i=Bars-2;
   PdmBuffer[i+1]=0;
   MdmBuffer[i+1]=0;
   if(counted_bars>=i) i=Bars-counted_bars-1;
   starti=i;
//----
   while(i>=0)
     {
      price_low=Low[i];
      price_high=High[i];
      //----
      pdm=price_high-High[i+1];
      mdm=Low[i+1]-price_low;
      if(pdm<0) pdm=0;  // +DM
      if(mdm<0) mdm=0;  // -DM
      if(pdm==mdm) { pdm=0; mdm=0; }
      else if(pdm<mdm) pdm=0;
           else if(mdm<pdm) mdm=0;
      //----
      double num1=MathAbs(price_high-price_low);
      double num2=MathAbs(price_high-Close[i+1]);
      double num3=MathAbs(price_low-Close[i+1]);
      tr=MathMax(num1,num2);
      tr=MathMax(tr,num3);
      //---- counting plus/minus direction
      if(tr==0) { PdmBuffer[i]=0; MdmBuffer[i]=0; TrBuffer[i]=0; }
      else      { PdmBuffer[i]=pdm; MdmBuffer[i]=mdm; TrBuffer[i]=tr; }
      //----
      i--;
     }
//---- last counted bar will be recounted
   if(counted_bars>0) counted_bars--;
   int limit=Bars-counted_bars;
//---- apply EMA to ±DI
   for(i=0; i<=limit; i++)
   {  //iMAOnArray
      PlusDiBuffer[i]=100 * iMAOnArray(PdmBuffer,Bars,ADXPeriod,0,MODE_EMA,i) / iMAOnArray(TrBuffer,Bars,ADXPeriod,0,MODE_EMA,i);
      MinusDiBuffer[i]=100 * iMAOnArray(MdmBuffer,Bars,ADXPeriod,0,MODE_EMA,i) / iMAOnArray(TrBuffer,Bars,ADXPeriod,0,MODE_EMA,i);
   }   
      
//---- Directional Movement (DX)
   i=Bars-2;
   TempBuffer[i+1]=0;
   i=starti;
   while(i>=0)
     {
      double div=MathAbs(PlusDiBuffer[i]+MinusDiBuffer[i]);
      if(div==0.00) TempBuffer[i]=0;
      else TempBuffer[i]=100*(MathAbs(PlusDiBuffer[i]-MinusDiBuffer[i])/div);
      i--;
     }
//---- ADX is exponential moving average on DX
   for(i=0; i<limit; i++)
      ADXBuffer[i]=iMAOnArray(TempBuffer,Bars,ADXPeriod,0,MODE_EMA,i);
//----
   return(0);
  }
//+------------------------------------------------------------------+--------------+

[Shino Unada]

//---- last counted bar will be recounted
   if(counted_bars>0) counted_bars--;
   int limit=Bars-counted_bars;

An "Array out of Range" error occurs because when "counted_bars" is 0, "limit" is equal to "Bars" 

[yyk03]

Nagisa Unada:

An "Array out of Range" error occurs because when "counted_bars" is 0, "limit" is equal to "Bars" 

Tried but still note fixed.

I'm rewriting the whole code based on some other approach now so might solve it eventually.

Thank you very much. 

[Shino Unada]

yum1573:

Tried but still note fixed.

I've not fixed your program, I'm just pointing out where it's causing the trouble.  Don't you understand that?

[yyk03]

Nagisa Unada:

I've not fixed your program, I'm just pointing out where it's causing the trouble.  Don't you understand that?

I think I understood. I checked & modified where you mentioned as well as other possible miscounting places but seems to be not that problem.

Thanks anyway:)