trying to get the number of decimal digits from a number (not a symbol)

Nguyen Van Anh 2020.10.25 06:18 #11

Hi everybody, use this one:

int DigitsCount(double number)

{

int digits = 0;

while (NormalizeDouble(number, digits) != number) {digits +=1;}

return digits;

}

SparlexScrewy Achievements 2021.09.28 06:47 #12

lippmaje #:

This is what I use. There's a maximum of 8 to keep it at a reasonable level.

Probably a bit more time consuming than calculating the remainder.

thank you very much for 3 line solution //it take me 2 day to find out i m in wrong-headed

if(true)

{ (DigitCountX != 9) &&(PrecisionSaveBack <= 0.00000009)&&( PrecisionSaveBack >= 0.00000000) ? DigitCountX = 8 : x = false;//>>>>>

(DigitCountX != 8) &&(PrecisionSaveBack <= 0.11111110)&&( PrecisionSaveBack >= 0.00000001) ? DigitCountX = 7 : x = false;//

(DigitCountX != 7) &&(PrecisionSaveBack <= 0.11111100)&&( PrecisionSaveBack >= 0.00000011) ? DigitCountX = 6 : x = false;//

(DigitCountX != 6) &&(PrecisionSaveBack <= 0.11111000)&&( PrecisionSaveBack >= 0.00000111) ? DigitCountX = 5 : x = false;//

(DigitCountX != 5) &&(PrecisionSaveBack <= 0.11110000)&&( PrecisionSaveBack >= 0.00001111) ? DigitCountX = 4 : x = false;///>>>>>>>>>.

(DigitCountX != 4) &&(PrecisionSaveBack <= 0.11100000)&&( PrecisionSaveBack >= 0.00011111) ? DigitCountX = 3 : x = false;

(DigitCountX != 3) &&(PrecisionSaveBack <= 0.11000000)&&( PrecisionSaveBack >= 0.00111111) ? DigitCountX = 2 : x = false;

(DigitCountX != 2) &&(PrecisionSaveBack <= 0.10000000)&&( PrecisionSaveBack >= 0.01111111) ? DigitCountX = 1 : x = false;

(DigitCountX != 1) &&(PrecisionSaveBack <= 1.00000000)&&( PrecisionSaveBack >= 0.11111111) ? DigitCountX = 0 : x = false;//

}

Styler - Developing programs Real and Generated Ticks Elliott Wave Theory -

Dretta 2021.11.04 02:24 #13

// returns number of digits in double or -1 if exceeds limit
int CountDigits(double number, int limit = 128)
{
   // locals
   int count = 0;

   // remove decimal component
   double decimal = MathAbs(number - (int) number);
   
   // loop for digit count
   if (decimal > 0.0)
      while (count < limit && decimal < 1.0 && !IsStopped())
      {
         decimal *= 10;
         count++;
      }

   // check digits not exceed limit
   if (count == limit)
      return(WRONG_VALUE);
      
   return(count);  
}

John Wangombe 2024.03.19 12:29 #14

may be you can try this..

int CountDigits_(double val){

string dstr = (string)(val);

int sf = StringFind(dstr,".",0);

int strlen = StringLen(dstr);

int digitsamount = (strlen-(sf+1));

return(digitsamount);

}

amrali 2024.03.19 16:04 #15

All functions posted before on this thread are WRONG!

either they return incorrect number of digits, or they get caught into infinite loops.

The only two valid functions that works in all cases are:

//+------------------------------------------------------------------+
//| Counts decimal places.                                           |
//| https://github.com/EarnForex/PositionSizer/tree/master&nbsp;          |
//+------------------------------------------------------------------+
int CountDecimalPlaces(double number)
{
    // 100 as maximum length of number.
    for (int i = 0; i < 100; i++)
    {
        double pwr = MathPow(10, i);
        if (MathRound(number * pwr) / pwr == number) return(i);
    }
    return(-1);
}

The second one is part of the Math Utils (MT4) - library for MetaTrader 4 https://www.mql5.com/en/code/25723

//+------------------------------------------------------------------+
//| Get number of decimal digits after the decimal point.            |
//+------------------------------------------------------------------+
int GetDigits(const double val)
  {
   int digits = 0;
   for(double pwr = 1; digits < 308 && MathRound(val * pwr) / pwr != val; pwr *= 10)
      digits++;
   return digits;
  }