_Digits is returning 10013 due to failures in price rounding

[Paul McGalloway]

This computer is going to get such a hiding.

I am so sick and tired of seeing the same `invalid_request` when MQL5 is doing this to itself.

Why is `NormalizeDouble` failing to actually adjust prices to their broker-specified decimal places?

Why?

This is MRP:

double TPIncrement = 200;

if(modify_take_profit){
      
         for(int i = request_total_positions - 1; i >= 0; i --){
         
            if(!PositionSelect(_Symbol)){
            
               string custom_subject = "Position Modification Error";
               string custom_message = "Unfortunately, we were unable to select the position from the ledger.";
               
               DiagnosticMessaging(custom_subject, custom_message);
               `
               break;
            
            }
            
            long request_pos_magic = PositionGetInteger(POSITION_MAGIC);
            
            if(request_pos_magic != UniqueChartIdentifier){
            
               continue;
            
            }
            
            ENUM_POSITION_TYPE   request_pos_type  =  (ENUM_POSITION_TYPE)PositionGetInteger(POSITION_TYPE);
            long                 request_pos_ticket=  PositionGetInteger(POSITION_TICKET);   
            double               request_pos_tp    =  NormalizeDouble(PositionGetDouble(POSITION_TP),_Digits);
            double               request_pos_sl    =  NormalizeDouble(PositionGetDouble(POSITION_SL),_Digits);
            double               request_bid       =  NormalizeDouble(SymbolInfoDouble(_Symbol, SYMBOL_BID),_Digits);
            double               request_ask       =  NormalizeDouble(SymbolInfoDouble(_Symbol, SYMBOL_ASK),_Digits); 
            double               modified_pos_tp   =  0;
                

            if (request_pos_type == POSITION_TYPE_BUY){
            
               modified_pos_tp = NormalizeDouble(request_pos_tp + (TPIncrement * _Point),
_Digits );
               
               OrderModifyRequest(request_pos_ticket,request_pos_sl,modified_pos_tp);   
            
            } else if (request_pos_type == POSITION_TYPE_SELL){
               
               modified_pos_tp = NormalizeDouble(request_pos_tp - (TPIncrement * _Point),
_Digits );
                                             
               OrderModifyRequest(request_pos_ticket, request_pos_sl, modified_pos_tp);
            
            } 
            
         }
      
      } 

Which calls the following:

#include <Trade\Trade.mqh> //Instatiate Trades Execution Library
#include <Trade\OrderInfo.mqh> //Instatiate Library for Orders Information
#include <Trade\PositionInfo.mqh> //Instatiate Library for Positions Information

bool OrderModifyRequest(ulong PositionTicket, double NewStopLoss, double NewTakeProfit) {
      
   MqlTradeRequest request;
   MqlTradeResult result;
   MqlTradeCheckResult check;   

   // Initialize the trade request for modifying the order
   request.action   = TRADE_ACTION_SLTP;       
   request.position = PositionTicket;                    
   request.tp       = NewTakeProfit; 
   request.sl       = NewStopLoss;            
   request.symbol   = PositionGetString(POSITION_SYMBOL);                   
   
   if(!OrderSend(request, result)) {
      
      Print(" Unfortunately, there was an error "+string(result.retcode)+" in modifying order #"+string(PositionTicket));
      
      return false;
   
   }
   
   Print("Order modification succeeded! Ticket: ", PositionTicket);
   
   return true;
   
}   What do I get?

....aaaand what do I get?

2025.04.15 14:03:08.660 2025.20.1.0 (USDJPY,H1) OrderModifyRequest Unfortunately, there was an error 10013 in modifying order #34179009 

...and then:

2025.04.15 13:36:41.986 Trades  '441134': failed modify #34179009 sell 1 USDJPY sl: 143.01000, tp: 142.41000 -> sl: 143.01000, tp: 142.21000 [Invalid request]

Can you spot the utterly stupid result here?.

Here's what I have tried (apart from everything);

1. I even printed the `_Digits` and it returned the correct number of digits,
2. I hardcoded the number of digits into the `NormalzeDouble's` positional argues, and it still rounded the sodding prices to 5 decimal places.

I am done.

Why does it sporadically go from printing 3dp pricing to 5 dp pricing?

Why does this thing think it can just blatantly ignore what I am telling it do to?

What is wrong with this thing?

[William Roeder]

1. Paul McGalloway: Why is `NormalizeDouble`

   You used NormalizeDouble, Its use is usually wrong, as it is in your case.

   1. Floating point has an infinite number of decimals, it's you were not understanding floating point and that some numbers can't be represented exactly. (like 1/10.)
                Double-precision floating-point format - Wikipedia, the free encyclopedia

      See also The == operand. - MQL4 programming forum (2013)

   2. Print out your values to the precision you want with DoubleToString - Conversion Functions - MQL4 Reference.

   3. SL/TP (stops) need to be normalized to tick size (not Point) — code fails on non-currencies.
                On 5Digit Broker Stops are only allowed to be placed on full pip values. How to find out in mql? - MQL4 programming forum #10 (2011)

      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 programming forum (2012)

   4. 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 non-currencies. So do it right.
                Trailing Bar Entry EA - MQL4 programming forum (2013)
                Bid/Ask: (No Need) to use NormalizeDouble in OrderSend - MQL4 programming forum (2012)

   5. Lot size must also be adjusted to a multiple of LotStep and check against min and max. If that is not a power of 1/10 then NormalizeDouble is wrong. Do it right.
                (MT4 2013)) (MT5 2022))

   6. MathRound() and NormalizeDouble() are rounding in a different way. Make it explicit.
                MT4:NormalizeDouble - MQL5 programming forum (2017)
                How to Normalize - Expert Advisors and Automated Trading - MQL5 programming forum (2017)

   7. Prices (and lots) you get from the terminal are already correct (normalized).

   8. PIP, Point, or Tick are all different in general.
                What is a TICK? - MQL4 programming forum (2014)

2. Use the debugger or print out your variables, including _LastError and prices and find out why. Do you really expect us to debug your code for you?
             Code debugging - Developing programs - MetaEditor Help
             Error Handling and Logging in MQL5 - MQL5 Articles (2015)
             Tracing, Debugging and Structural Analysis of Source Code - MQL5 Articles (2011)
             Introduction to MQL5: How to write simple Expert Advisor and Custom Indicator - MQL5 Articles (2010)

[Paul McGalloway]

William Roeder #:
You used NormalizeDouble, Its use is usually wrong, as it is in your case.

Nope, the whole thing is a piece of shit and not fit for purpose. 

I’m seriously about to lose my temper and smash this computer into a million pieces. I’m so sick to the back teeth of nothing doing what I tell it to. I’ve been an MQL editor for 10 years, and I’ve never come across something this utterly stupid in all that time.