MQL4 Code Help : Volume Check and Adjust

[shanmugapradeep]

Article URL : The checks a trading robot must pass before publication in the Market - MQL5 Articles


I am getting Error 131. To resolve this, I am trying something like Volume Error Handling. It update value automatically.

Buy_Lot_Size = MathMax(SymbolInfoDouble(buy_random_symbol, SYMBOL_VOLUME_MIN), MathMin(Buy_Lot_Size, SymbolInfoDouble(buy_random_symbol, SYMBOL_VOLUME_MAX)));
   Sell_Lot_Size = MathMax(SymbolInfoDouble(sell_random_symbol, SYMBOL_VOLUME_MIN), MathMin(Sell_Lot_Size, SymbolInfoDouble(sell_random_symbol, SYMBOL_VOLUME_MAX)));

or

Buy_Lot_Size = MathMax(MarketInfo(buy_random_symbol, MODE_MINLOT), MathMin(Buy_Lot_Size, MarketInfo(buy_random_symbol, MODE_MAXLOT)));
   Sell_Lot_Size = MathMax(MarketInfo(sell_random_symbol, MODE_MINLOT), MathMin(Sell_Lot_Size, MarketInfo(sell_random_symbol, MODE_MAXLOT)));

Instead of

//+------------------------------------------------------------------+
//| Check the correctness of the order volume                        |
//+------------------------------------------------------------------+
bool CheckVolumeValue(double volume,string &description)
  {
//--- minimal allowed volume for trade operations
   double min_volume=SymbolInfoDouble(Symbol(),SYMBOL_VOLUME_MIN);
   if(volume<min_volume)
     {
      description=StringFormat("Volume is less than the minimal allowed SYMBOL_VOLUME_MIN=%.2f",min_volume);
      return(false);
     }
 
//--- maximal allowed volume of trade operations
   double max_volume=SymbolInfoDouble(Symbol(),SYMBOL_VOLUME_MAX);
   if(volume>max_volume)
     {
      description=StringFormat("Volume is greater than the maximal allowed SYMBOL_VOLUME_MAX=%.2f",max_volume);
      return(false);
     }
 
//--- get minimal step of volume changing
   double volume_step=SymbolInfoDouble(Symbol(),SYMBOL_VOLUME_STEP);
 
   int ratio=(int)MathRound(volume/volume_step);
   if(MathAbs(ratio*volume_step-volume)>0.0000001)
     {
      description=StringFormat("Volume is not a multiple of the minimal step SYMBOL_VOLUME_STEP=%.2f, the closest correct volume is %.2f",
                               volume_step,ratio*volume_step);
      return(false);
     }
   description="Correct volume value";
   return(true);
  }

But my both of the code is not working. What wrong with my code. it does exact same and even better than article URL. it also adjust the Volume size after comparison.

 

[Enivid]

If your code are the top two snippets, it fails to adjust for the volume step value. I recommend printing the calculated volume before using it in OrderSend() to see which values are causing error 131 in your tests.