problem with partial close

[Hany Mhmd Th Abrahym Aljml]

hi everyone,

I have an issue with my partial close code

The calculated LotSizeBuy = 0.04875487 and OrderLots() = 0.04 

when i try to Normalize LotSizeBuy it gives 0.05 which isn't equal to 0.04 

is there any suggestion so the condition ( OrderLots() == LotSizeBuy ) can be true ?  

void Partial_Close()
{
  for(int  n=OrdersTotal()-1; n>=0; n--)
   {
    select=OrderSelect(n,SELECT_BY_POS,MODE_TRADES);
     {
      RiskAmount =  AccountBalance()*RiskPercent/100;
      double LotSizeBuy=NormalizeDouble(RiskAmount/(((OrderOpenPrice()-OrderStopLoss())/pips)*10),2);
      double LotSizeSell=NormalizeDouble(RiskAmount/(((OrderStopLoss()-OrderOpenPrice())/pips)*10),2);
      
       {
        if(OrderLots() == LotSizeBuy)
       //
        if (OrderType()==OP_BUY)
        if((Ask - OrderOpenPrice())>((PartialClosePercent/100)*(OrderTakeProfit() - OrderOpenPrice())))
        close=OrderClose(OrderTicket(),OrderLots()/2,Bid,3);
       }
      
       {  
        if(NormalizeDouble(OrderLots(),1) == NormalizeDouble(LotSizeSell,1))
        if (OrderType()==OP_SELL)
        if((OrderOpenPrice()-Ask)>((PartialClosePercent/100)*(OrderOpenPrice()-OrderTakeProfit())))
        close=OrderClose(OrderTicket(),OrderLots()/2,Ask,3);
       }
     }
   }  
}

[honest_knave]

Checking for equality with doubles is always troublesome.

If you must do so, define an acceptable deviation and check if the difference between the doubles is within that deviation.

Also remember that you must always check that your lotsize complies with min lot, max lot and lot step.

[William Roeder]

Hany Taha:

The calculated LotSizeBuy = 0.04875487 and OrderLots() = 0.04 

when i try to Normalize LotSizeBuy it gives 0.05 which isn't equal to 0.04 

is there any suggestion so the condition ( OrderLots() == LotSizeBuy ) can be true ? 

1. 0.048 rounded to two digits is 0.05. Why are you comparing the sizes? If you want to close it close it.

2. Do NOT use NormalizeDouble, EVER. For ANY Reason. It's a kludge, don't use it. It's use is always wrong

   • SL/TP (stops) need to be normalized to tick size (not Point.) (On 5Digit Broker Stops are only allowed to be placed on full pip values. How to find out in mql? - MQL4 forum) and abide by the limits Requirements and Limitations in Making Trades - Appendixes - MQL4 Tutorial and that requires understanding floating point equality Can price != price ? - MQL4 forum
   • Open price for pending orders need to be adjusted. On Currencies, Point == TickSize, so you will get the same answer, but it won't work on Metals. So do it right: Trailing Bar Entry EA - MQL4 forum or Bid/Ask: (No Need) to use NormalizeDouble in OrderSend - MQL4 forum
   • Lot size must also be adjusted to a multiple of LotStep. If that is not a power of 1/10 then NormalizeDouble is wrong. Do it right.

3. close=OrderClose(OrderTicket(),OrderLots()/2,Bid,3);
   The close amount must be a multiple of LotStep and be between min and max. The remaining amount must be also. Normalize OrderLots()/2 properly and test.

   ---

4. Check your return codes What are Function return values ? How do I use them ? - MQL4 forum and Common Errors in MQL4 Programs and How to Avoid Them - MQL4 Articles
   

[Hany Mhmd Th Abrahym Aljml]

Thnx all guys I tried honest_knave's idea and it worked fine

 NOTES : (1) I changed plan and decided to close 2/3 of OrderLots instead of 1/2 OrderLots 

              (2) Numbers 1.01 & 2.9 are obtained by experiment and covers almost all LotSize probabilities 

now the comparison code is :

if(LotSizeBuy /  OrderLots() > 1.01 && LotSizeBuy /  OrderLots() < 2.9)