noobie question

can someone explain to me how this EA calculate the lot size for each trade cause I understand very litlle in mt4 languages.

//| Calculate optimal lot size |
//+------------------------------------------------------------------+
double LotsOptimized()
{
double lot=Lots;
int orders=HistoryTotal(); // history orders total
int losses=0; // number of losses orders without a break
//---- select lot size
lot=NormalizeDouble(AccountFreeMargin()*MaximumRisk/1000.0,1);
//---- calcuulate number of losses orders without a break
if(DecreaseFactor<0)
{
for(int i=orders-1;i>=0;i--)
{
if(OrderSelect(i,SELECT_BY_POS,MODE_HISTORY)==false) { Print("Error in history!"); break; }
if(OrderSymbol()!=Symbol() || OrderType()>OP_SELL) continue;
//----
if(OrderProfit()>0) break;
if(OrderProfit()<0) losses++;
}
if(losses>1) lot=NormalizeDouble(lot-lot*losses/DecreaseFactor,1);
}
//---- return lot size
if(lot<0.01) lot=0.01;
return(lot);

from this line:
double lot=Lots;
...
if(losses>1) lot=NormalizeDouble(lot-lot*losses/DecreaseFactor,1);

first, you have initial lot size, named Lots (look at extern variable, at the top of the code)
let's say Lots = 0.2.
then there is DecreaseFactor, lets say DecreaseFactor=5
if your consecutive losses equals to 2 (losses greater than 1)
then lot size = 0.2 - 0.2*2/5 = 0.2 - 0.4/5 = 0.2 - 0.08 = 0.12
it is rounded to 1 decimal point => NormalizeDouble(...,1)
0.12 => 0.1

hope this help

Thank you I understand now!!!!

There is something else I don<t understand. If the account free margin is 3000 and the max risk is .01 the lot size should be
3000* .01 / 1000 = .03 but the EA takes only a .01 lot size. at few occasion the EA open .1 lot when the account grow to 5000 but at this point it should open 5000*.01/1000 =.05 lot.

//| Calculate optimal lot size |
//+------------------------------------------------------------------+
double LotsOptimized()
{
double lot=Lots;
int orders=HistoryTotal(); // history orders total
int losses=0; // number of losses orders without a break
//---- select lot size
lot=NormalizeDouble(AccountFreeMarg in()*MaximumRisk/1000.0,1);
//---- calcuulate number of losses orders without a break
if(DecreaseFactor<0)
{
for(int i=orders-1;i>=0;i--)
{
if(OrderSelect(i,SELECT_BY_POS,MODE _HISTORY)==false) { Print("Error in history!"); break; }
if(OrderSymbol()!=Symbol() || OrderType()>OP_SELL) continue;
//----
if(OrderProfit()>0) break;
if(OrderProfit()<0) losses++;
}
if(losses>1) lot=NormalizeDouble(lot-lot*losses/DecreaseFactor,1);
}
//---- return lot size
if(lot<0.01) lot=0.01;
return(lot);

http://cdn.forexfactory.com/images/misc/progress.gif

I still dont understand why the Ea does not open the proper lot size.

Cqn womeone tell me what the 1 stand for in the code....

lot=NormalizeDouble(AccountFreeMarg in()*MaximumRisk/1000.0,1);

hi,

it seems there is wrong logic with my last reply. the function first calculated lot size not from Lots variable, but from :
lot=NormalizeDouble(AccountFreeMarg in()*MaximumRisk/1000.0,1);

firstly, about NormalizeDouble(..,1), it will return value with 1 digit precision.

for example, var1 = 5/8 = 0.625.
NormalizeDouble(var1,2) = 0.63 >>> 2 digit after decimal point
NormalizeDouble(var1,1) = 0.6 >>> 1 digit after decimal point



form your case,
AccountFreeMargin=3000
MaximumRisk = 0.01
AccountFreeMargin*MaximumRisk/1000 = 3000*0.01/1000 = 0.03
lot=NormalizeDouble(0.03,1) = 0.0 !!! the "3" is omitted because it is in the second position, counted from the left after decimal point

then before returning the result:
//---- return lot size
if(lot<0.01) lot=0.01;
return(lot);
so, because the calculated lot above result 0 which is smaller then 0.01, the function returned 0.01;

last thing, you should use if(DecreaseFactor>0) instead if(DecreaseFactor<0), and make sure the value of DecreaseFactor is a positive value (for example 3)

hope this help