Attachments: passing a varible between functions help

passing a varible between functions help

#1
First Post: May 13, 2010 1:14pm May 13, 2010 1:14pm

censura
| Joined Sep 2006 | Status: Trader | 405 Posts

Hi i have various functions in my ea i am building but wondered how i can pass varibles from i called function to be used by other functions or the main start part of the program

eg i have a array BarMa[i] which holds the values of the Ma of the last 10 bars but wish to use these values say if (BarMa[0] > BarMa[9]) in another part of the program

hope you can help

#2
May 13, 2010 3:16pm May 13, 2010 3:16pm

CodeMeister
Joined Sep 2009 | Status: Making Code While Making Pips | 1,672 Posts

Functions are normally declared with parameters to allow you to do this. It is poor programming practise to use statically declared values in functions. So it is good to get in the habit of passing variables as parameters. There is lots of help in the MetaEditor Online Help secton to explain what I mean.

#3
Edited 5:57pm May 13, 2010 5:55pm | Edited 5:57pm

spotfxtrader
| Joined May 2010 | Status: Trader | 10 Posts

double function(double ma1, double ma2){
if(ma1 > ma2)return(yourvariable);
}

from where you call your function {function(ma1, ma2);}

that should work

#4
May 14, 2010 10:22am May 14, 2010 10:22am

censura
| Joined Sep 2006 | Status: Trader | 405 Posts

Hi i tried this but get error function definition unexpected

double Trend()
{
double Trend(double ma1, double ma2)

int (CurrentDirection = 0);

if(ma1>ma2)CurrentDirection = 1; //up
if(ma1<ma2)CurrentDirection = 2; //down
if(ma1==ma2)CurrentDirection = 0; //no trend

Print ("current direction" ,CurrentDirection);

return(CurrentDirection);
}

I want the CurrentDirection value 1,2 or 0 to be passed to the main program

also is Trend(BarMa[9],BarMa[0]);
how i should call the function or by Trend();

I am trying to pull values from the the previous function which collects values for BarMa[0] to BarMa[9] and use these values as inputs for the paramaters in the trend function
any help appritiated

#5
May 14, 2010 3:18pm May 14, 2010 3:18pm

hanover
Joined Sep 2006 | Status: ... | 8,114 Posts

Quoting censura

Disliked

Hi i tried this but get error function definition unexpected

Ignored

The most common cause of this error is an unmatched opening brace {
i.e. a missing closing brace }
prior to the definition of the function.

If you want to post all of your code, I'll find it for you. I use an advanced programmers' editor called Notepad++ (it can be downloaded free from here). Among its many features is its ability to colorize matching braces and parentheses, and 'fold' (expand/collapse) code between nested braces. I do my editing using Notepad++, and then paste the code back into MetaEditor merely for the purpose of compiling it.

#6
May 14, 2010 4:49pm May 14, 2010 4:49pm

hayseed
Joined Nov 2006 | Status: Trader | 4,420 Posts

hey censura..... looks like a couple errors..... compare your code to this......h

Inserted Code

 
int Trend(double ma1, double ma2)
{
int CurrentDirection = 0;
if(ma1 >  ma2)  CurrentDirection = 1; //up
if(ma1 <  ma2)  CurrentDirection = 2; //down
if(ma1 == ma2) CurrentDirection = 0; //no trend 
 
Print ("current direction" ,CurrentDirection);
return(CurrentDirection);
}

to trade and code, keep both simple... no call to impress....h

#7
May 14, 2010 8:59pm May 14, 2010 8:59pm

spotfxtrader
| Joined May 2010 | Status: Trader | 10 Posts

try this

Inserted Code

double Trend(double ma1, double ma2){
 //this is how you declare and initialize a variable
   int CurrentDirection = 0;
      
      if(ma1>ma2)CurrentDirection = 1; //up
      else if(ma1<ma2)CurrentDirection = 2; //down
      else if(ma1==ma2)CurrentDirection = 0; //no trend 
      
            
      Print ("current direction" ,CurrentDirection);
     
    return(CurrentDirection);
 }

int start(){
double DIR;
DIR=Trend(ma1, ma2);
//then you can use DIR
return(0);
}

#8
May 14, 2010 9:56pm May 14, 2010 9:56pm

antoine
| Joined Oct 2008 | Status: mobydickInc. Import Export Mnfctr | 19 Posts

Quote

Disliked

I do my editing using Notepad++, and then paste the code back into MetaEditor merely for the purpose of compiling it.

mq4 files can be compiled through notepad++ with the Run (F5) menu and the command string:

Inserted Code

"C:\Program Files\FxPro - MetaTrader\MetaLang.exe" "$(FULL_CURRENT_PATH)"

Obviously with MetaLang.exe 's path modified to your own metatrader directory. I haven't found a way to autorefresh the indicator in MT4 navigator and chart so after all I still use MetaEditor.

#9
May 15, 2010 1:44am May 15, 2010 1:44am

censura
| Joined Sep 2006 | Status: Trader | 405 Posts

Quoting spotfxtrader

try this

Inserted Code

 
double Trend(double ma1, double ma2){
 //this is how you declare and initialize a variable
   int CurrentDirection = 0;
 
      if(ma1>ma2)CurrentDirection = 1; //up
      else if(ma1<ma2)CurrentDirection = 2; //down
      else if(ma1==ma2)CurrentDirection = 0; //no trend 
 
 
      Print ("current direction" ,CurrentDirection);
 
    return(CurrentDirection);
 }
 
int start(){
double DIR;
DIR=Trend(ma1, ma2);
//then you can use DIR
return(0);
}

nt start()
{
//----

Hi got the above error ? sorry dont know why
if (TimeCurrent() >= StrToTime ("18:11:00") && TimeCurrent() <= StrToTime ("18:11:50"))
{
collectma();
entryprices();
Trend(double ma1, double ma2);
DIR=Trend(ma1, ma2);
}

{
return(0);
}

//----
return(0);
}

#10
May 15, 2010 2:36am May 15, 2010 2:36am

hanover
Joined Sep 2006 | Status: ... | 8,114 Posts

Quoting antoine

Disliked
mq4 files can be compiled through notepad++ with the Run (F5) menu and the command string:
Inserted Code
"C:Program FilesFxPro - MetaTraderMetaLang.exe" "$(FULL_CURRENT_PATH)"
Obviously with MetaLang.exe 's path modified to your own metatrader directory. I haven't found a way to autorefresh the indicator in MT4 navigator and chart so after all I still use MetaEditor.
Ignored

Many thanks for the info.

#11
May 15, 2010 4:39am May 15, 2010 4:39am

censura
| Joined Sep 2006 | Status: Trader | 405 Posts

Quoting spotfxtrader

try this

Inserted Code

 
double Trend(double ma1, double ma2){
 //this is how you declare and initialize a variable
   int CurrentDirection = 0;
 
      if(ma1>ma2)CurrentDirection = 1; //up
      else if(ma1<ma2)CurrentDirection = 2; //down
      else if(ma1==ma2)CurrentDirection = 0; //no trend 
 
 
      Print ("current direction" ,CurrentDirection);
 
    return(CurrentDirection);
 }
 
int start(){
double DIR;
DIR=Trend(ma1, ma2);
//then you can use DIR
return(0);
}

I have the following function which collects the ma's of the last 10 bars to use in the main program and other functions.

initially i need to get the BarMa[9] and BarMa[0] and compare them and store them in ma1 and ma2 for use in another called function Trend(ma1,ma2);
..............................................................................
Functiondouble collectma()
{
if (MACycle==false) // load MA Values for last 10 bars

for(bar=0; bar<Limit; bar++) // collect MA Values store in array BarMa

BarMa[bar] = iMA(NULL,PERIOD_M1,40,0,MODE_SMA,PRICE_CLOSE,bar);

double ma1=BarMa[9];
double ma2=BarMa[0];

MACycle = true; // Cause count to set to 1 to ensure cycles once

}
...........................................................................

Then in the main part of the program i have

int start()
{

collectma; //call function to collect last 10 bars MA's store in
//BarMa array and assign double ma1 =BarMa[9],
//ma1 =BarMa[0];

Trend(ma1,ma2); // compare ma1 and ma2 and provide signal 1,2,or 0
DIR=Trend(ma1, ma2); // pass result to varibleDIR for use later

}

return;
if someone can look over this to see if it makes sense i would be very happy

#12
May 15, 2010 9:30am May 15, 2010 9:30am

antoine
| Joined Oct 2008 | Status: mobydickInc. Import Export Mnfctr | 19 Posts

Here's a simplified indicator to visualize what I think you may be trying to do - specifically the 3 lines in the middle of the start function.

(As far as I understand EA's only work with the current bar, meaning the i baroffset always equals 0, so just remove the i 's in the iMa(.., i + ..))

And now the EA just uses the DIR value for its buy/sell decision.

On the other hand, I'm not really sure if the MACycle is useful for anything. This arrangement seems to work ok without it, at least in indicator form.

Inserted Code

#property indicator_separate_window

double   ma1, ma2, DIR, DIRindicator[];

void start() {
   for(int i=Bars-IndicatorCounted();i>=0;i--) {


      ma1 = iMA( NULL, PERIOD_M1, 40, 0, MODE_SMA, PRICE_CLOSE, i + 0 );
      ma2 = iMA( NULL, PERIOD_M1, 40, 0, MODE_SMA, PRICE_CLOSE, i + 9 );
      DIR = Trend( ma1 , ma2 );


      DIRindicator[i] = DIR;
   }
}

double Trend(double ma1, double ma2) {
   int CurrentDirection = 0;
   if(ma1>ma2)CurrentDirection = 1; //up
      else if(ma1<ma2)CurrentDirection = 2; //down
         else if(ma1==ma2)CurrentDirection = 0; //no trend 
   //Print ("current direction" ,CurrentDirection);
   return(CurrentDirection);
}

void init() {
   SetIndexStyle(0,DRAW_HISTOGRAM); SetIndexBuffer(0,DIRindicator);
}

Attached File(s)

__ffMaPlay100515.mq4 < 1 KB | 312 downloads

#13
May 15, 2010 12:54pm May 15, 2010 12:54pm

censura
| Joined Sep 2006 | Status: Trader | 405 Posts

Thank you for your help let me clarify the rules for my ea

At a specific time say 2am gmt
Collect last 10 bar ma values
Compare the 10th bar to the current -1 bar and get trend dir
Ie bar 10 ma < bar 1ma trend up

This is trade signal although I need to test that there has been no counter trend
In last 10 bars = 3 consecutive bars in opp dir to trend ie trend up bar 10,9,8 trend down no trade
Bar 10 and 9 down but 8 up ok. Thus I test each bar against trend in a countet
So if trend up it could be counter starts at 0 and then bar 10 to 9 down counter -1 then bar
9 to 8 down counter - 2 the 8 to 7 up or flat counter resets to 0 and we carry on till all 10 bars analyised if counter ever hits - 3 or 3 and is opp to trend signal don't trade ie if buy signal bar 10<bar 1 and counter hit -3 no trade

That's it , thank you

#14
May 15, 2010 6:17pm May 15, 2010 6:17pm

antoine
| Joined Oct 2008 | Status: mobydickInc. Import Export Mnfctr | 19 Posts

Ok, here's an indicator quickbacktest logic of how I understand the complete method. The main signal gets generated on trend = ma[0] vs ma[9], then the signal gets cancelled if there is at least a 3 bar continous countertrend against it. I commented out the time filter completely because it blocks all signals and needs to be tweaked anyway if translated to proper EA form. The backtest trades size 1 and exits+reverses on opposite entry signal (and ignores ba spread).

This clean version just plots profit curve and has clearer code to figure out.

Inserted Code

//antoine ff 100515: quickbacktest censura's time & ma trend entry idea
#property indicator_separate_window

double   ma[10], position= 0, profit[];

void start() {
   for(int i= Bars-IndicatorCounted(); i>=0; i--) {

      //on prior bar's position
      profit[i]= profit[i+1] + position *(Close[i]-Close[i+1]); 

      for(int j=0; j<10; j++)
         ma[j] = iMA( NULL, 0, 40, 0, MODE_SMA, PRICE_CLOSE, i +j);

      double trend= ma[0]-ma[9];
      
      bool  signalLG= false, signalSH= false;

      //generate main signal based on trend ma[0] - ma[9]
      if (trend>0) signalLG= true;  
      if (trend<0) signalSH= true;
      
      //cup & cdn keep count of countertrend sequences: up & dn
      int   cup= 0, cdn= 0;         

      //cancelling main signal if countertrend goes >2 bars
      for( j=0; j<9; j++) {         
         if ( ma[j] > ma[j+1] ) { cup++; cdn=0; if (cup>2) signalSH= false; }
         if ( ma[j] < ma[j+1] ) { cdn++; cup=0; if (cdn>2) signalLG= false; }
      }

      if (signalLG) position= +1;   //position long
      if (signalSH) position= -1;   //position short
   }
}

void init() { SetIndexStyle(0,DRAW_LINE); SetIndexBuffer(0,profit); }

And this development version plots the trend signal (green), countertrendup sequence (blue), countertrenddown sequence (red) and the final trade long/short position (black).

Inserted Code

//antoine ff 100515: quickbacktest censura's time & ma trend entry idea
#property indicator_separate_window
#property indicator_buffers 4
#property indicator_color2 Blue
#property indicator_color3 Red
#property indicator_color4 Lime

double   ma[10], position= 0, profit[], test1[], test2[], test3[];

void start() {
   for(int i= Bars-IndicatorCounted(); i>=0; i--) {
   
//      profit[i]= profit[i+1] +(position *(Close[i]-Close[i+1])); //on prior bar's position
//      if (Time[i]<StrToTime("18:11:00") || Time[i]>StrToTime("18:11:50")) continue;

      for(int j=0; j<10; j++)
         ma[j] = iMA( NULL, 0, 40, 0, MODE_SMA, PRICE_CLOSE, i +j);

      double trend= ma[0]-ma[9];
      
      bool  signalLG= false, signalSH= false;
      if (trend>0) signalLG= true;  //generate main signal based on trend ma[0] - ma[9]
      if (trend<0) signalSH= true;
      
      if (signalLG) test3[i]= +5;
      if (signalSH) test3[i]= -5;
      
      int   cup= 0, cdn= 0;         //cup & cdn keep count of countertrend sequences: up & dn
      for( j=0; j<9; j++) {         //cancelling main signal if countertrend goes >2 bars
         if ( ma[j] > ma[j+1] ) { cup++; cdn=0; if (cup>2) signalSH= false; }
         if ( ma[j] < ma[j+1] ) { cdn++; cup=0; if (cdn>2) signalLG= false; }
      }

      if (signalLG) position= +1;   //position long
      if (signalSH) position= -1;   //position short
      
      test1[i]= 0+cup; 
      test2[i]= 0-cdn;
      profit[i]= 10* position;
   }
}

void init() {
   SetIndexStyle(0,DRAW_LINE); SetIndexBuffer(0,profit);
   SetIndexStyle(1,DRAW_LINE); SetIndexBuffer(1,test1);
   SetIndexStyle(2,DRAW_LINE); SetIndexBuffer(2,test2);
   SetIndexStyle(3,DRAW_LINE); SetIndexBuffer(3,test3);

}

Fun puzzle, enjoy.

Attached File(s)

__ffMaPlayBacktest100515.mq4 1 KB | 331 downloads

__ffMaPlayBacktestDEV_100515.mq4 2 KB | 351 downloads

#15
May 16, 2010 1:22am May 16, 2010 1:22am

censura
| Joined Sep 2006 | Status: Trader | 405 Posts

Thank you very much, i have learnt alot already from all your input
it is really helpful to have the opportunity to draw from your skill and experiance. I hope in the future i can contribuite something back which helps others

#16
Last Post: May 16, 2010 2:16am May 16, 2010 2:16am

antoine
| Joined Oct 2008 | Status: mobydickInc. Import Export Mnfctr | 19 Posts

You're welcome. I just know basic stuff about mql from tutorials http://forum.mql4.com/c/forum/2006/1...nsv1htod10.zip and some C programming stuff http://www.cprogramming.com/tutorial/c/lesson1.html just reading/browsing them for design/logic ideas, and then using MetaEditor built-in help and language reference (F1) for details on how to use each function only when it's needed. And a whole lot of playing around = practice. Enjoy.

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