[req] Help calculating lot size

I am demo testing and I want to code my EA in a manner that would result in trade sizes of 0.2 lots for every 1000 of Account Balance.

The closest I could get to that goal is the following, assuming a balance of 5000

double lot=1;

lot=NormalizeDouble(MathFloor(AccountFreeMargin()*200)/1,1);

Re: [req] Help calculating lot size

//external variables

extern bool UseMoneyManagement = false;

extern double DecreaseFactor = 5;

extern int Risk = 10;

extern double InitialLot=0.1;

extern bool AccountIsMicro=false;

double Lots()

{

if(UseMoneyManagement==false) return(InitialLot);

double lots;

int orders=HistoryTotal();

int losses=0;

int decimalPlaces=1;

if(AccountIsMicro==true) decimalPlaces=2;

lots=NormalizeDouble((AccountFreeMargin()*Risk/1000.0)/100,decimalPlaces);

StoppedOut = LastTradeStoppedOut();

if (StoppedOut==true)

{

if(AccountIsMicro==false) lots=0.1;

if(AccountIsMicro==true) lots=0.01;

}

if(lots<0.1 && AccountIsMicro==false) lots=0.1;

if(lots<0.01 && AccountIsMicro==true) lots=0.01;

double maxlot = MarketInfo(Symbol(), MODE_MAXLOT);

if (MyMaxLot>0)

{

if (lots>MyMaxLot)

return (MyMaxLot);

}

if(lots>maxlot) lots=maxlot-1;

return(lots);

}

bool LastTradeStoppedOut()

{

int cnt, total;

datetime NextTime;

bool Stopped=false;

NextTime = 0;

total = HistoryTotal();

for (cnt = total - 1; cnt >= 0; cnt--)

{

OrderSelect (cnt, SELECT_BY_POS, MODE_HISTORY);

if(OrderSymbol()==Symbol() && OrderMagicNumber() == Magic)

{

Stopped = false;

if (OrderType() == OP_BUY)

{

if (OrderClosePrice() - OrderOpenPrice() < 0)

{

Stopped = true;

}

cnt = 0;

}

if (OrderType() == OP_SELL)

{

if (OrderOpenPrice() - OrderClosePrice() < 0)

{

Stopped = true;

}

cnt = 0;

}

}

}

if (Stopped)

{

StopTime = OrderCloseTime() + MinutesToDelay*60;

}

return (Stopped);

}

Re: [req] Help calculating lot size

Ok here you go.. put it in strategy tester and play with your variables to test..

http://www.mediafire.com/?sharekey=2f912bd94f9b924a9bf8d6369220dcabe04e75f6e8ebb871

//+------------------------------------------------------------------+
//|                                                    LotTester.mq4 |
//|                                                                  |
//|                                                                  |
//+------------------------------------------------------------------+
#property copyright ""
#property link      ""

extern double Lots = 0.2;
extern double MinBalance = 1000;

//+------------------------------------------------------------------+
//| expert initialization function                                   |
//+------------------------------------------------------------------+
int init()
 {
//----
  
//----
  return(0);
 }
 
 
//+------------------------------------------------------------------+
//| expert deinitialization function                                 |
//+------------------------------------------------------------------+
int deinit()
 {
//----
  
//----
  return(0);
 }
 
 
//+------------------------------------------------------------------+
//| expert start function                                            |
//+------------------------------------------------------------------+
int start()
 {
//----
  Comment("AccountBalance: " +DoubleToStr(AccountBalance(),2)+"  Lots: "+ DoubleToStr(CalcLots(),2)); 
  return(0);
//----
  return(0);
 }
 
 
//+------------------------------------------------------------------+

//+------------------------------------------------------------------+
//| expert CalcLots function                                            |
//+------------------------------------------------------------------+
double CalcLots()
{
//----
  double iLots;
  if (AccountBalance()>MinBalance)
  {
   iLots= NormalizeDouble((AccountFreeMargin()*(Lots*100)/1000)/100,2);

  } 
   else iLots = Lots;
//----    
  return (iLots);
}