How to code? - Page 114

Berkis · #**1131** (**permalink**) 08-07-2008, 04:26 PM

Maybe someone can help me, i dont know if its possible or very hard to do it, but I would be very happy to have such tool. I need a simple EA or script with a help of MT4-LevelStop-Reverse indicator. I want my orders to be closed when i get opposite signal from indicator. If i have opened long order and get short signal the EA or script closes order and if i am short open order and get long sygnal the EA or script closes my short position. That's it

Thank you in advance

matrixebiz · #**1132** (**permalink**) 08-08-2008, 02:42 AM

How do I setup Time Trading hours in an EA?

I was trying this;
int TradeHour;

if(Hour()<9 && Hour() >17) TradeHour = false;

but doesn't seem to be obeying the rule, it just trades whenever and I do have && TradeHour in my buy/sell statements.

Thanks

wolfe · #**1133** (**permalink**) 08-08-2008, 04:32 AM

Quote:

Originally Posted by matrixebiz

How do I setup Time Trading hours in an EA?

I was trying this;
int TradeHour;

if(Hour()<9 && Hour() >17) TradeHour = false;

but doesn't seem to be obeying the rule, it just trades whenever and I do have && TradeHour in my buy/sell statements.

Thanks

Have you tried defining TradeHour as a boolean instead of an integer?

PHP Code:


			
bool TradeHour;

if ((Hour()<9)  &&  (Hour() >17)){ TradeHour = false;}

Plus you may need the additional brackets.

luxinterior · #**1134** (**permalink**) 08-08-2008, 04:41 AM

Quote:

Originally Posted by matrixebiz

How do I setup Time Trading hours in an EA?

I was trying this;
int TradeHour;

if(Hour()<9 && Hour() >17) TradeHour = false;

but doesn't seem to be obeying the rule, it just trades whenever and I do have && TradeHour in my buy/sell statements.

Thanks

How can Hour() be less than 9 AND greater than 17?? Did you mean Or (||)?

Lux

wolfe · #**1135** (**permalink**) 08-08-2008, 04:46 AM

Quote:

Originally Posted by luxinterior

How can Hour() be less than 9 AND greater than 17?? Did you mean Or (||)?

Lux

Good point luxinterior! That's a definite problem. I missed that.

matrixebiz · #**1136** (**permalink**) 08-08-2008, 05:44 AM

Sorry, I meant ||

and I was trying this to;
//+---------Trade hour variables------------------
// if (Hour() < StartHour) TradeHourS = false;
// if (Hour() > EndHour) TradeHourE = false;

So if StartHour=5 and EndHour=17 it should only trade within those hours correct?

But it trade anytime still ?? is it a problem using the Strategy Tester?

luxinterior · #**1137** (**permalink**) 08-08-2008, 05:50 AM

Why not just use the example straight from the help file?

Code:

  bool is_siesta=false;
  if(Hour()>=12 || Hour()<17)
     is_siesta=true;

Lux

gorgoroth · #**1138** (**permalink**) 08-08-2008, 10:58 AM

Hi everyone,

I've developed a set of functions to manage configuration settings from an EA.
Those functions are exported by a c++ DLL and each of the exported function has the __stdcall calling convetion requested my MQL4.

My problem arises when a function need to return a string to the EA.

Naturally the function cannot:
- return a pointer to a local variabile (variable goes out of scope)
- return a pointer to a dll global variable (problems with concurrent access)
- return a pointer to a heap allocated string (need functions to free memory to be called from the EA: I don't not like this approach)

So i resolved to pass a string and string size from the EA. Es:

Code:

string buffer;

GetString( buffer, 30 );

and from the c++ dll, something like this

Code:

void __stdcall GetString( LPTSTR buffer, int BufSize )
{
    // Read a string from a some source
    ....
    // -1 to take into account the terminating null character
    StringCchCopy( buffer, BufSize-1, ReadStringFromASource );
}

Here starts the weird behaviour of MQL managing strings returned from a DLL.

using the following code:

Code:

string buffer;
GetString( buffer, 30 );

the first time buffer contains the right string. A first question arises: buffer is not initialized but after calling GetString it contains the string returned. I have to suppose that MQL allocates space for a string variable when it's declared.

Next time GetString() is called the string returned seems to be truncated to the length-1 of the previous string length and not resetted as expected because of the 'string buffer;' statement.

Tried even:

Code:

string buffer = "                              "; // 'allocate' 30 blank characters
GetString( buffer, StringLen(buffer) );

but after the first time, when the execution returns to this code, the assignment of buffer does not work any more and buffer still contains the previous read string, and it seems it can only contains the number of characters of his content.

At first I have thought that the null character is not handled very well by MQL and modified the c++ code like this ...

Code:

CopyMemory( buffer, ReadStringFromASource, min(BufferSize,ReadStringFromASourceLength) );

and not adding the terminating null character.

But when called from MQL, no string at all is returning.

Has someone an answer ?

matrixebiz · #**1139** (**permalink**) 08-08-2008, 11:37 AM

Quote:

Originally Posted by luxinterior

Why not just use the example straight from the help file?

Code:

  bool is_siesta=false;
  if(Hour()>=12 || Hour()<17)
     is_siesta=true;

Lux

yeah, I tried that to;
bool TradeHour=false;

if(Hour()>=12 || Hour()<17) TradeHour=true

but the OR line won't work because if Hour happens to be 22 then it satisfies the first part "if(Hour()>=12" and Still trades whenever it wants and I did add && TradeHour to by Buy/Sell statements. The second example I gave should to the trick, I don't get it

gorgoroth · #**1140** (**permalink**) 08-08-2008, 11:48 AM

Quote:

Originally Posted by luxinterior

Why not just use the example straight from the help file?

Code:

  bool is_siesta=false;
  if(Hour()>=12 || Hour()<17)
     is_siesta=true;

Lux

I think if your goal is to trade between 12:00 and 17:00 you simply have to do the following:

Code:

  bool TradingEnabled=false; // Global variable
...
...
  TradingEnabled=false; // Reset every tic run
  if(Hour()>=12 && Hour()<17)
     TradingEnabled=true;
...
...
    if( TradingEnabled ) 
    {
         // Trading logic here
    }
...
...

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

LinkBacks (?) LinkBack to this Thread: http://www.forex-tsd.com/metatrader-programming/554-how-code.html
Posted By	For	Type	Date
Need an experienced programmer? - Page 2	Post #0	Refback	09-24-2008 07:24 AM

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
How to code this?	iscuba11	Metatrader 4 mql 4 - Development course	1	08-03-2007 05:22 PM

Register in Forex TSD!
Trading Systems Leaders in this forum (automated trading systems) are winning more than 3000 pips in a month (30000$ investing one lot every time). Click here to register and get more information