Thread: EA Coding

Hello everyone,
I'm kind of new to EA.
I would like to find out where i can learn how to write an EA.
Should i be using the MetaEditor to write them?
How can i do a test, i know there's this thing called Strategy Tester in MT4 but sometimes when i run certain EA that i got from here, i can't see any results.
It's as if the EA doesn't do anything. I'm unsure if i got the steps wrong or is the EA corrupted.
When i load the EA in to my chart, i read somewhere i should see a smiley face... but i see a sad one. Is this right?

I just would like to learn how to write my own EA as i want to back test a strategy that i'm thinking of.

Please help me.
Thank You.

Here you can learn MQL4:

MQL4 Tutorial

Thank You K-B.
Very much appreciated.

..... I'm stuck on a line of code and wonder if either you or somebody else can help me please.

This block of code is being used within an EA to process orders in the account history.

Code:

// --- Process Closed Orders

  while (Closed_Order_Total > PosC)
   {
    if (OrderSelect(PosC,SELECT_BY_POS,MODE_HISTORY))
     {
      if(OrderType() == OP_BUY) {Dir = 1;}
      if(OrderType() == OP_SELL) {Dir = -1;}
      
      string OS = OrderSymbol();
      double OP = OrderProfit()+OrderSwap()+OrderCommission();
//      double Pips_Won = Dir * (OrderClosePrice()-OrderOpenPrice())/Point;
      double Pips_Won = Dir * (OrderClosePrice()-OrderOpenPrice())/MarketInfo(OS,MODE_POINT);
      datetime TradeTime = MathAbs(OrderCloseTime() - OrderOpenTime());

      int    Magic = OrderMagicNumber();
      
      if (OS == Pair_A && Magic == Magic_A) {OT_Pair_A++; OP_Pair_A = OP_Pair_A+OP; TradeTime_Pair_A=TradeTime_Pair_A+TradeTime; Pips_Won_Pair_A=Pips_Won_Pair_A+Pips_Won; if(OP>=0){OW_Pair_A++; WT_Pair_A = WT_Pair_A+OP;} if(OP<0){OL_Pair_A++; LT_Pair_A = LT_Pair_A+OP;}}
      if (OS == Pair_B && Magic == Magic_B) {OT_Pair_B++; OP_Pair_B = OP_Pair_B+OP; TradeTime_Pair_B=TradeTime_Pair_B+TradeTime; Pips_Won_Pair_B=Pips_Won_Pair_B+Pips_Won; if(OP>=0){OW_Pair_B++; WT_Pair_B = WT_Pair_B+OP;} if(OP<0){OL_Pair_B++; LT_Pair_B = LT_Pair_B+OP;}}
      if (OS == Pair_C && Magic == Magic_C) {OT_Pair_C++; OP_Pair_C = OP_Pair_C+OP; TradeTime_Pair_C=TradeTime_Pair_C+TradeTime; Pips_Won_Pair_C=Pips_Won_Pair_C+Pips_Won; if(OP>=0){OW_Pair_C++; WT_Pair_C = WT_Pair_C+OP;} if(OP<0){OL_Pair_C++; LT_Pair_C = LT_Pair_C+OP;}}
      if (OS == Pair_D && Magic == Magic_D) {OT_Pair_D++; OP_Pair_D = OP_Pair_D+OP; TradeTime_Pair_D=TradeTime_Pair_D+TradeTime; Pips_Won_Pair_D=Pips_Won_Pair_D+Pips_Won; if(OP>=0){OW_Pair_D++; WT_Pair_D = WT_Pair_D+OP;} if(OP<0){OL_Pair_D++; LT_Pair_D = LT_Pair_D+OP;}}
      if (OS == Pair_E && Magic == Magic_E) {OT_Pair_E++; OP_Pair_E = OP_Pair_E+OP; TradeTime_Pair_E=TradeTime_Pair_E+TradeTime; Pips_Won_Pair_E=Pips_Won_Pair_E+Pips_Won; if(OP>=0){OW_Pair_E++; WT_Pair_E = WT_Pair_E+OP;} if(OP<0){OL_Pair_E++; LT_Pair_E = LT_Pair_E+OP;}}
      if (OS == Pair_F && Magic == Magic_F) {OT_Pair_F++; OP_Pair_F = OP_Pair_F+OP; TradeTime_Pair_F=TradeTime_Pair_F+TradeTime; Pips_Won_Pair_F=Pips_Won_Pair_F+Pips_Won; if(OP>=0){OW_Pair_F++; WT_Pair_F = WT_Pair_F+OP;} if(OP<0){OL_Pair_F++; LT_Pair_F = LT_Pair_F+OP;}}
      if (OS == Pair_G && Magic == Magic_G) {OT_Pair_G++; OP_Pair_G = OP_Pair_G+OP; TradeTime_Pair_G=TradeTime_Pair_G+TradeTime; Pips_Won_Pair_G=Pips_Won_Pair_G+Pips_Won; if(OP>=0){OW_Pair_G++; WT_Pair_G = WT_Pair_G+OP;} if(OP<0){OL_Pair_G++; LT_Pair_G = LT_Pair_G+OP;}}
      if (OS == Pair_H && Magic == Magic_H) {OT_Pair_H++; OP_Pair_H = OP_Pair_H+OP; TradeTime_Pair_H=TradeTime_Pair_H+TradeTime; Pips_Won_Pair_H=Pips_Won_Pair_H+Pips_Won; if(OP>=0){OW_Pair_H++; WT_Pair_H = WT_Pair_H+OP;} if(OP<0){OL_Pair_H++; LT_Pair_H = LT_Pair_H+OP;}}
      if (OS == Pair_I && Magic == Magic_I) {OT_Pair_I++; OP_Pair_I = OP_Pair_I+OP; TradeTime_Pair_I=TradeTime_Pair_I+TradeTime; Pips_Won_Pair_I=Pips_Won_Pair_I+Pips_Won; if(OP>=0){OW_Pair_I++; WT_Pair_I = WT_Pair_I+OP;} if(OP<0){OL_Pair_I++; LT_Pair_I = LT_Pair_I+OP;}}
      if (OS == Pair_J && Magic == Magic_J) {OT_Pair_J++; OP_Pair_J = OP_Pair_J+OP; TradeTime_Pair_J=TradeTime_Pair_J+TradeTime; Pips_Won_Pair_J=Pips_Won_Pair_J+Pips_Won; if(OP>=0){OW_Pair_J++; WT_Pair_J = WT_Pair_J+OP;} if(OP<0){OL_Pair_J++; LT_Pair_J = LT_Pair_J+OP;}}
      
      
     }
    PosC++;
    }

I am satisfied that the code is working properly and I am able to carry out the remaining processes of the EA with one exception.

When I use the line that I have rem'd out and highlighted in red, the EA works but, because it uses the value of Point for the symbol that the EA is attached to, this is no good for processing symbols other than the current symbol unless their Point happens to be the same.

When I substitute the red line for the line that I have highlighted in blue using the MarketInfo() function, the EA returns a Zero Divide error message. I can't see what I am doing wrong.

Can somebody help please, as this is driving me crazy.

Thanks for your suggestion, Funyoo, but it still returns the Zero Divide error unfortunately.

For that to happen, it suggests that the MarketInfo() function itself is returning a zero value and I don't understand why.

It certainly is strange, Funyoo, and thanks for your other suggestion. I didn't really want to go that route though if I could avoid it.

I'd like to be able to resolve it an easier way if possible, but I'm lacking ideas at the moment.

Are there any other suggestions or an explanation please?

Well I knew there was an easy solution.

Replacing Pips_Won with its formula in each of the 10 lines of conditions gets it to work as intended. I don't really understand why this should be, but at least I can move on again.

Thanks for your help, Funyoo.