Attachments: loop: passing Array to function question?

loop: passing Array to function question?

#1
First Post: Edited 4:22pm Nov 7, 2011 4:03pm | Edited 4:22pm

M_j
| Joined Nov 2008 | Status: Trader | 1,344 Posts

hi,

maybe someone knows how to do that correctly.

I would like to loop through different TF Intervals and pass a different Arrays to my function:

Something like that: The //Block in question

PHP Code

int interval = 1;
int _PeriodM1 = 10;
int _PeriodM5 = 50;

double dArOpenPriceM1[];
double dArOpenPriceM5[];

//Somewhere
ArrayCopySeries(dArOpenPriceM1, MODE_OPEN, sPairName, PERIOD_M1);
ArrayCopySeries(dArOpenPriceM5, MODE_OPEN, sPairName, PERIOD_M5);
=====================



//Block in question
if (interval == PERIOD_M1) {
    myFunc(_PeriodM1, dArOpenPriceM1);
}
else if (interval == PERIOD_M5) {
    myFunc(_PeriodM5, dArOpenPriceM5);
}


=====================
//Helper function
void myFunc(int _Period, double _dArOpenPrice[]) {
    //Do my thing
}

instead of the //Block in question

I would like to do something like:

PHP Code

int HelperArray[2];
HelperArray[0] = _PeriodM1;
HelperArray[1] = _PeriodM5;

for (int x = 0; x < 2; x++) {
    myFunc(HelperArray[x], double _dArOpenPrice[])  
// don't know how to pass here the correct one array
}

I guess someone must have done something like this way before me (if it is possible in MT4)
- and hope you are kind enough to take a couple of minutes to share - thanks a lot.

__Thanks__ MJ

#2
Nov 7, 2011 5:18pm Nov 7, 2011 5:18pm

cyber1
Joined Jan 2011 | Status: Trader | 1,299 Posts

The following is a script that shows how to loop through each TF and Pair

Save it to the Scripts folder, click the Experts tab and then execute the script.

PHP Code

//+------------------------------------------------------------------+
//|                                                        close.mq4 |
//|                      Copyright © 2004, MetaQuotes Software Corp. |
//|                                       http://www.metaquotes.net/ |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2004, MetaQuotes Software Corp."
#property link      "http://www.metaquotes.net/"

//+------------------------------------------------------------------+
//| script  |
//+------------------------------------------------------------------+
int start(){

int TimeFrame,TF;
string dSymbol;

//currencies
string Currencies[]={"EURUSD","GBPUSD","AUDUSD"};
 int count = ArraySize(Currencies);

// TimeFrames
int TimeFrames[] = {30,60,240,1440,10080};
int counttf = ArraySize(TimeFrames);

for (int x=0; x<count; x++){
    dSymbol = Currencies[x];  

for (int xe=0; xe<counttf; xe++){
    TF = TimeFrames[xe];  
Print(dSymbol+" - "+TF);


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

#3
Edited 6:37pm Nov 7, 2011 6:08pm | Edited 6:37pm

bandung
Joined Apr 2010 | Status: Trader | 642 Posts

Quoting M_j

Disliked

hi,

maybe someone knows how to do that correctly.

I would like to loop through different TF Intervals and pass a different Arrays to my function:

Something like that: The //Block in question

[php]int interval = 1;
int _PeriodM1 = 10;
int _PeriodM5 = 50;

double dArOpenPriceM1[];
double dArOpenPriceM5[];

//Somewhere
ArrayCopySeries(dArOpenPriceM1, MODE_OPEN, sPairName, PERIOD_M1);
ArrayCopySeries(dArOpenPriceM5, MODE_OPEN, sPairName, PERIOD_M5);
=====================

//Block...

Ignored

hi mj,
you can merge that array open price, but you need to have fixed size array for locating different tf start index

something like this:

PHP Code

#define ARR_OPEN_SIZE  2000

double daOpenPrice[];
double dArOpenPriceM1[ARR_OPEN_SIZE];
double dArOpenPriceM5[ARR_OPEN_SIZE];
  
int start()
{
   int _PeriodM1 = 10;
   int _PeriodM5 = 50;

   int HelperArray[2];
   HelperArray[0] = _PeriodM1;
   HelperArray[1] = _PeriodM5;
   
   //int size = 1000
   
   ArrayResize(daOpenPrice, 2 * ARR_OPEN_SIZE);
   
   ArrayCopySeries(dArOpenPriceM1, MODE_OPEN, Symbol(), PERIOD_M1);
   ArrayCopySeries(dArOpenPriceM5, MODE_OPEN, Symbol(), PERIOD_M5);
   
   //-->copy dArOpenPriceM1 & dArOpenPriceM5 to daOpenPrice   
      //--- #0 M1, started from 0 * ARR_OPEN_SIZE
      ArrayCopy(daOpenPrice, dArOpenPriceM1, 0 * ARR_OPEN_SIZE, 0, ARR_OPEN_SIZE);   
      //--- #1 M5, started from 1 * ARR_OPEN_SIZE
      ArrayCopy(daOpenPrice, dArOpenPriceM5, 1 * ARR_OPEN_SIZE, 0, ARR_OPEN_SIZE); 
   //<--copy dArOpenPriceM1 & dArOpenPriceM5 to daOpenPrice
   
   
   for (int x = 0; x < 2; x++) myFunc(HelperArray[x], x*ARR_OPEN_SIZE) ; 
   
}  

void myFunc(int _Period, int startidx) 
{    
    //--Test
    for (int i=0; i<5; i++)    
      Print("Per : ", _Period, " Open Price@", i, " : ", daOpenPrice[startidx + i]);                
}

...

#4
Nov 8, 2011 2:53am Nov 8, 2011 2:53am

M_j
| Joined Nov 2008 | Status: Trader | 1,344 Posts

Quoting cyber1

Disliked

The following is a script that shows how to loop through each TF and Pair

Save it to the Scripts folder, click the Experts tab and then execute the script.

[php]//+------------------------------------------------------------------+
//| close.mq4 |
//| Copyright 2004, MetaQuotes Software Corp. |
//| http://www.metaquotes.net/ |
//+------------------------------------------------------------------+
#property copyright "Copyright...

Ignored

cyber1, Thanks a lot for taking time.

It's not exactly what I was looking for. I have arrays (ArrayCopySeries but also others) depending on each TF.

__Thanks__ MJ

#5
Edited 4:21am Nov 8, 2011 3:11am | Edited 4:21am

M_j
| Joined Nov 2008 | Status: Trader | 1,344 Posts

Quoting bandung

hi mj,
you can merge that array open price, but you need to have fixed size array for locating different tf start index

something like this:

PHP Code

 //-->copy dArOpenPriceM1 & dArOpenPriceM5 to daOpenPrice   
      //--- #0 M1, started from 0 * ARR_OPEN_SIZE
      ArrayCopy(daOpenPrice, dArOpenPriceM1, 0 * ARR_OPEN_SIZE, 0, ARR_OPEN_SIZE);   
      //--- #1 M5, started from 1 * ARR_OPEN_SIZE
      ArrayCopy(daOpenPrice, dArOpenPriceM5, 1 * ARR_OPEN_SIZE, 0, ARR_OPEN_SIZE); 
   //<--copy dArOpenPriceM1 & dArOpenPriceM5 to daOpenPrice
   

   
}

bandung,
thanks a lot - glancing at it, it seems to be one possible option - had not thought about it before. So this is a helpful point. I will play a bit around with it.

In case someone else has an other approach where I can avoid the extra copy part (above part) ( for 9 TF there are 36 ArrayCopySeries) I would appropriate your input too.

__Thanks__ MJ

#6
Nov 8, 2011 4:19am Nov 8, 2011 4:19am

M_j
| Joined Nov 2008 | Status: Trader | 1,344 Posts

Just something I noticed:

Quoting bandung

hi mj,
you can merge that array open price, but you need to have fixed size array for locating different tf start index

something like this:

PHP Code

#define ARR_OPEN_SIZE  2000

double daOpenPrice[];
double dArOpenPriceM1[ARR_OPEN_SIZE];
double dArOpenPriceM5[ARR_OPEN_SIZE];
  
int start()
{
   ArrayCopySeries(dArOpenPriceM1, MODE_OPEN, Symbol(), PERIOD_M1);
   ArrayCopySeries(dArOpenPriceM5, MODE_OPEN, Symbol(), PERIOD_M5);
}

I never passed a fixed size array to ArrayCopySeries so I wanted to check it out.

It seems to get anyway ReSized so it does not really have any effect.

Picture below:

PHP Code

#define ARR_OPEN_SIZE  2000


datetime        dtArTimeM1[]; 
datetime        dtArTimeM5[];  
  
datetime        dtArTimeM1_limit[ARR_OPEN_SIZE];  
datetime        dtArTimeM5_limit[ARR_OPEN_SIZE];  

 
int start()
{    Comment("");
    int beforedtArTimeM1Size = ArraySize(dtArTimeM1);
    int beforedtdtArTimeM5Size = ArraySize(dtArTimeM5);
    int beforedtdtArTimeM1_limitSize = ArraySize(dtArTimeM1_limit);
    int beforedtdtArTimeM5_limitSize = ArraySize(dtArTimeM5_limit);
    

    ArrayCopySeries(dtArTimeM1, MODE_TIME, Symbol(), PERIOD_M1);
    ArrayCopySeries(dtArTimeM5, MODE_TIME, Symbol(), PERIOD_M5);
    
    ArrayCopySeries(dtArTimeM1_limit, MODE_TIME, Symbol(), PERIOD_M1);
    ArrayCopySeries(dtArTimeM5_limit, MODE_TIME, Symbol(), PERIOD_M5);
    
    
     Comment ("n"+ "Before: NORMAL: ArraySize(dtArTimeM1): "+ beforedtArTimeM1Size + " ArraySize(dtArTimeM5): "+ beforedtdtArTimeM5Size
            + "nn"+"Before: LIMIT: ArraySize(dtArTimeM1_limit): "+ beforedtdtArTimeM1_limitSize + " ArraySize(dtArTimeM5_limit): "+ beforedtdtArTimeM5_limitSize
     
            +"n"
            + "nn"+"AFTER NORMAL: ArraySize(dtArTimeM1): "+ ArraySize(dtArTimeM1) + " ArraySize(dtArTimeM5): "+ ArraySize(dtArTimeM5)
            + "nn"+"AFTER LIMIT: ArraySize(dtArTimeM1_limit): "+ ArraySize(dtArTimeM1_limit) + " ArraySize(dtArTimeM5_limit): "+ ArraySize(dtArTimeM5_limit)
            
            +"n"
            + "nn"+"NORMAL LAST: M1: "+TimeToStr(dtArTimeM1[ArraySize(dtArTimeM1) -1])+" M5: "+TimeToStr(dtArTimeM5[ArraySize(dtArTimeM5) -1])
            + "nn"+"LIMIT  LAST: M1: "+TimeToStr(dtArTimeM1_limit[ArraySize(dtArTimeM1_limit) -1])+" M5: "+TimeToStr(dtArTimeM5_limit[ArraySize(dtArTimeM5_limit) -1])
            
            +"n"
            + "nn"+"NORMAL FIRST: M1: "+TimeToStr(dtArTimeM1[0])+" M5: "+TimeToStr(dtArTimeM5[0])
            + "nn"+"LIMIT  FIRST: M1: "+TimeToStr(dtArTimeM1_limit[0])+" M5: "+TimeToStr(dtArTimeM5_limit[0])
            );
}

Attached Image

__Thanks__ MJ

#7
Nov 8, 2011 5:13am Nov 8, 2011 5:13am

bandung
Joined Apr 2010 | Status: Trader | 642 Posts

Quoting M_j

Disliked

Just something I noticed:

I never passed a fixed size array to ArrayCopySeries so I wanted to check it out.

It seems to get anyway ReSized so it does not really have any effect.

Picture below:

[php]
#define ARR_OPEN_SIZE 2000

datetime dtArTimeM1[];
datetime dtArTimeM5[];

datetime dtArTimeM1_limit[ARR_OPEN_SIZE];
datetime dtArTimeM5_limit[ARR_OPEN_SIZE];

int start()
{ Comment("");
int beforedtArTimeM1Size = ArraySize(dtArTimeM1);
int beforedtdtArTimeM5Size...

Ignored

so do I

, i try it and yes it resized
but it doesn't matter because this block will only copy as much as ARR_OPEN_SIZE

Inserted Code

   //-->copy dArOpenPriceM1 & dArOpenPriceM5 to daOpenPrice   
      //--- #0 M1, started from 0 * ARR_OPEN_SIZE
      ArrayCopy(daOpenPrice, dArOpenPriceM1, 0*ARR_OPEN_SIZE, 0, [b]ARR_OPEN_SIZE[/b]);   
      //--- #1 M5, started from 1 * ARR_OPEN_SIZE
      ArrayCopy(daOpenPrice, dArOpenPriceM5, 1*ARR_OPEN_SIZE, 0, [b]ARR_OPEN_SIZE[/b]); 
   //<--copy dArOpenPriceM1 & dArOpenPriceM5 to daOpenPrice
   
   Comment(
     "Array daOpenPrice>>M1@[0] ", DoubleToStr(daOpenPrice[0], Digits), " M5@[2000] ", DoubleToStr(daOpenPrice[2000], Digits)
   , "niOpen>>M1 bar#0 ", DoubleToStr(iOpen(NULL, PERIOD_M1, 0), Digits), " M5 bar#0 ", DoubleToStr(iOpen(NULL, PERIOD_M5, 0), Digits) 
   );

Attached Image (click to enlarge)

Click to Enlarge

Name: test.png
Size: 41 KB

...

#8
Nov 8, 2011 5:37am Nov 8, 2011 5:37am

M_j
| Joined Nov 2008 | Status: Trader | 1,344 Posts

Quoting bandung

Disliked

so do I , i try it and yes it resized
but it doesn't matter because this block will only copy as much as ARR_OPEN_SIZE

Ignored

Yes - was just curious as I never did pass such arrays - but the general idea would work.

I guess also with arbitrary offsets - just have to pass those (I do that with other arrays already.)

Thanks for the general idea - if no one else has some even better approaches - I will give this a try in a real indi.

Very kind of you.

__Thanks__ MJ

#9
Last Post: Edited 6:15am Nov 8, 2011 5:54am | Edited 6:15am

M_j
| Joined Nov 2008 | Status: Trader | 1,344 Posts

There is something else I'm thinking of:

instead of of passing the Array e.g. dArOpenPriceM1

ArrayCopySeries(dArOpenPriceM1, MODE_OPEN, Symbol(), PERIOD_M1);

I could do in my function for each bar a:
double iOpen( string symbol, int timeframe, int shift)

and only pass the different TimeFrame values

__Thanks__ MJ

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