Once..begin sometimes triggered twice [SOLVED]

JoshM · Postby **JoshM** » 08 Jul 2012

Using MultiCharts Version 8.0 Release (Build 5620) I noticed that the once begin statement sometimes is triggered twice. For example, the following indicator:

Code: Select all


once begin 



	Print(FormatTime("HH:mm:ss", ComputerDateTime), 

		" DateTime of bar: ", FormatDate("dd-MM-yy", ELDateToDateTime(Date)), 

		FormatTime(" HH:mm:ss ", ELTimeToDateTime_s(Time_s)),

		" BarStatus: ", BarStatus(1),

		" BarNumber: ", CurrentBar + MaxBarsBack - 1);



end;

Gives:

Code: Select all


21:09:32 DateTime of bar: 03-10-11 08:00:04  BarStatus:    2.00 BarNumber:    1.00

(Which is correct). Now add a Plot() statement to the code:

Code: Select all


once begin 



	Print(FormatTime("HH:mm:ss", ComputerDateTime), 

		" DateTime of bar: ", FormatDate("dd-MM-yy", ELDateToDateTime(Date)), 

		FormatTime(" HH:mm:ss ", ELTimeToDateTime_s(Time_s)),

		" BarStatus: ", BarStatus(1),

		" BarNumber: ", CurrentBar + MaxBarsBack - 1);



end;





Plot1(XAverage(Close, 20), "EMA");

The output now becomes:

Code: Select all


21:10:25 DateTime of bar: 03-10-11 08:00:04  BarStatus:    2.00 BarNumber:    1.00

21:10:25 DateTime of bar: 03-10-11 08:00:30  BarStatus:    2.00 BarNumber:    6.00

How come the once..begin statement is triggered twice now? Who knows what I'm missing?

Workaround attempt #1
Using a "CurrentBar = 1" check in combination with once still gives twice the output:

Code: Select all


once (CurrentBar = 1) begin 



	Print(FormatTime("HH:mm:ss", ComputerDateTime), 

		" DateTime of bar: ", FormatDate("dd-MM-yy", ELDateToDateTime(Date)), 

		FormatTime(" HH:mm:ss ", ELTimeToDateTime_s(Time_s)),

		" BarStatus: ", BarStatus(1),

		" BarNumber: ", CurrentBar + MaxBarsBack - 1);



end;





Plot1(XAverage(Close, 20), "EMA");

Code: Select all


21:15:30 DateTime of bar: 03-10-11 08:00:04  BarStatus:    2.00 BarNumber:    1.00

21:15:30 DateTime of bar: 03-10-11 08:00:30  BarStatus:    2.00 BarNumber:    6.00

Workaround attempt #2
Using a variable to keep track of whether or not the code segment is already run also doesn't work:

Code: Select all


Variables:

	IntraBarPersist OnceBeginTriggered(False);

	

if (OnceBeginTriggered = False) then begin 



	Print(FormatTime("HH:mm:ss", ComputerDateTime), 

		" DateTime of bar: ", FormatDate("dd-MM-yy", ELDateToDateTime(Date)), 

		FormatTime(" HH:mm:ss ", ELTimeToDateTime_s(Time_s)),

		" BarStatus: ", BarStatus(1),

		" BarNumber: ", CurrentBar + MaxBarsBack - 1);



	OnceBeginTriggered = True;

	

end;



Plot1(XAverage(Close, 20), "EMA");

Gives:

Code: Select all


21:19:17 DateTime of bar: 03-10-11 08:00:04  BarStatus:    2.00 BarNumber:    1.00

21:19:17 DateTime of bar: 03-10-11 08:00:30  BarStatus:    2.00 BarNumber:    6.00

Dru · Postby **Dru** » 10 Jul 2012

It is auto maximum number of bars back calculations ... Set up MaxBarsStudyWillReference manually to 20 and look on results.
The algorithm's work is looks like:
1) Set MaxBB = 0. Calculate. Detect that we need 1 BB. Break (Status Off).
2) Set MaxBB = 6. Calculate. Detect that we need *** BB. Break (Status Off).
3) Set MaxBB = *** + N. Calculate. Ok.

JoshM · Postby **JoshM** » 10 Jul 2012

It is auto maximum number of bars back calculations ... Set up MaxBarsStudyWillReference manually to 20 and look on results.
The algorithm's work is looks like:
1) Set MaxBB = 0. Calculate. Detect that we need 1 BB. Break (Status Off).
2) Set MaxBB = 6. Calculate. Detect that we need *** BB. Break (Status Off).
3) Set MaxBB = *** + N. Calculate. Ok.

This is very insightful, thanks Dru.

You're right; as long as the SetMaxBarsBack > 1, the once begin is triggered once instead of twice. Apparently, the number of bars back needs to be more than one, irrespective of the amount of bars that are actually referenced by the indicator (20 in this example).

For example:

Code: Select all


SetMaxBarsBack(2);

	

once begin 



	Print(FormatTime("HH:mm:ss", ComputerDateTime), 

		" DateTime of bar: ", FormatDate("dd-MM-yy", ELDateToDateTime(Date)), 

		FormatTime(" HH:mm:ss ", ELTimeToDateTime_s(Time_s)),

		" BarStatus: ", BarStatus(1),

		" BarNumber: ", CurrentBar + MaxBarsBack);



	

end;



Plot1(XAverage(Close, 20), "EMA");

Gives

Code: Select all


15:27:37 DateTime of bar: 01-01-12 23:09:00  BarStatus:    2.00 BarNumber:    3.00

However, I still think it would be a good idea if MultiCharts reconsiders Once-Begin, since it "doesn't work as expected" (that is, from my standpoint).

arjfca · Postby **arjfca** » 13 Nov 2012

It is auto maximum number of bars back calculations ... Set up MaxBarsStudyWillReference manually to 20 and look on results.
The algorithm's work is looks like:
1) Set MaxBB = 0. Calculate. Detect that we need 1 BB. Break (Status Off).
2) Set MaxBB = 6. Calculate. Detect that we need *** BB. Break (Status Off).
3) Set MaxBB = *** + N. Calculate. Ok.

Hello Dru / JoshM

Strange, the SetMaxBarsBack(2); does'nt work for me. Is is worst when I use this variable.

The "Once Begin" is triggered many many when I use it. Meaning, the "Once begin" is not seen and all code is run on nearly every pass. When not set, "Once begin" is triggered twice only

Martin

arjfca · Postby **arjfca** » 14 Nov 2012

Hello

Any reason why Once Begin codes lines are repeated twice?

I got some initialization code that I have put inside a

Code: Select all

Once Begin

   ...

   ...

end;

I see that user JoshM as issued a similar post about the subject and
user DRU as issued a solution by seting the

SetBarsMaxBack (2) >1 to resolve the problem

viewtopic.php?f=1&t=10592&hilit=+once+begin+#p51935

But the solution is not working in my case.

I even try to put my code inside If barnumber = 1 then ... do the initialization
Even with that condition, initialization code line are repeated

Is there a solution or MC is aware of the problem and will give a corrective later?

Martin

Henry MultiСharts · Postby **Henry MultiСharts** » 14 Nov 2012

It is auto maximum number of bars back calculations ... Set up MaxBarsStudyWillReference manually to 20 and look on results.
The algorithm's work is looks like:
1) Set MaxBB = 0. Calculate. Detect that we need 1 BB. Break (Status Off).
2) Set MaxBB = 6. Calculate. Detect that we need *** BB. Break (Status Off).
3) Set MaxBB = *** + N. Calculate. Ok.
Hello Dru / JoshM

Strange, the SetMaxBarsBack(2); does'nt work for me. Is is worst when I use this variable.

The "Once Begin" is triggered many many when I use it. Meaning, the "Once begin" is not seen and all code is run on nearly every pass. When not set, "Once begin" is triggered twice only

Martin

Hello Martin,

Probably your code requires more than two bars for calculation.
Please try to increase SetMaxBarsBack value and post your sample code here if you still have the issue.

Henry MultiСharts · Postby **Henry MultiСharts** » 14 Nov 2012

Hello

Any reason why Once Begin codes lines are repeated twice?

I got some initialization code that I have put inside a
Code: Select all
Once Begin ... ... end;
I see that user JoshM as issued a similar post about the subject and
user DRU as issued a solution by seting the

SetBarsMaxBack (2) >1 to resolve the problem

viewtopic.php?f=1&t=10592&hilit=+once+begin+#p51935

But the solution is not working in my case.

I even try to put my code inside If barnumber = 1 then ... do the initialization
Even with that condition, initialization code line are repeated

Is there a solution or MC is aware of the problem and will give a corrective later?

Martin

Hello Martin,

Probably your code requires more than two bars for calculation.
Please try to increase SetMaxBarsBack value and post your sample code here if you still have the issue.

arjfca · Postby **arjfca** » 14 Nov 2012

Hello Martin,

Probably your code requires more than two bars for calculation.
Please try to increase SetMaxBarsBack value and post your sample code here if you still have the issue.

Hello Henry

Result for setBarMaxBack: My code may be difficult to reproduce since I do have special function and dll include in it. The attached picture is for setBarMaxBack(51):

// setBarMaxBack not set: Two set of line code is printed

setBarMaxBack(2): Printed output line is multiple. I did not count but I suspect more than 10 set of line code is printed

setBarMaxBack(51):Printed two set of code line.

setBarMaxBack(100): Same result as with (51), two set of code line are printed.

Martin

Code: Select all






Once  begin		

		Cbarnumber = Barnumber;

		ScaleValue = ScaleValue_Calc(Barinterval);

		scale = scaleString; 

 	 	NameInstrument = GetSymbolName;

		BarCompleted = "";

		Targettime = referenceTime + delay;

		Targettime = Machinetime + delay;    

    	referenceTime = machineTime;  	// Saving a reference of the time

	     

		//Get the name of the Excel File

		Sstop = splitstring(GVGetNamedString("StartStopMC_GV","Error1"),1);	 // the path of the Excel file reside on the 2' place on the string

		Sbook = splitstring(GVGetNamedString("StartStopMC_GV","Error2_SBook"),2);	 // the path of the Excel file reside on the 2' place on the string

		Ssheet = splitstring(GVGetNamedString("StartStopMC_GV","Error3_Ssheet"),3);	 // the path of the Excel file reside on the 2' place on the string

		Print (Sbook, " ", Ssheet);

		

		//Initilized the New EleXcel.dll

		XLStarted = ELXL_Initialize ;//Initialise the ELeXcel .DLL

		WorksheetReady = ELXL_WithSheet(sbook,Ssheet) ;

      If XlStarted = true and WorkSheetReady = True then XLstarted = true else Xlstarted = False;

      If xlstarted then print ("XlStarted with scale: ", scale) else print ("ELEXcel not started");

		

		SbookBack = Sbook;		

		//Print ("_Sstop: ", Sstop, "  Sbook: ", Sbook, "  Ssheet: ",Ssheet);

  

		//Send to Excel the Scale and the name of the instrument

	  



	 	If UseData2 then begin



		 	InitString = NameInstrument + comma + Scale + comma + GetSymbolName data2 + comma + scale data2;

     	end

     	else begin

     		InitString = NameInstrument + comma + Scale + comma +comma +comma + comma;

     	end; 

     

     //If Sbook <> SbookBack then print ("0 ", Sbook);

	 	// Condition0 = XLO.TextA1(sBook,sSheet,Cell_,InitString);							// Capture the scale 

       If XlStarted then begin 

          Condition0 =  ELXL_SetCellString( InitStringCell , Initstring ) ;	

       

       end;

       

     //If Condition0 = False then print ("Cond0_1 ", condition0);

     gowithcode=false  ;

     // print ("Once:", sbook, "  ", ssheet);        

end; //End of initialisation

Henry MultiСharts · Postby **Henry MultiСharts** » 14 Nov 2012

Martin, please provide a sample code that can be compiled by all forum members and that will reproduce the problem. If you are using custom functions-please export the study with dependent functions. That is not possible to provide any insight on the code you have posted above.

arjfca · Postby **arjfca** » 14 Nov 2012

Martin, please provide a sample code that can be compiled by all forum members and that will reproduce the problem. If you are using custom functions-please export the study with dependent functions. That is not possible to provide any insight on the code you have posted above.

OK

I think I found a solution path idea

My workspace use two Instruments. When only one is used, the code inside the Once Begin /end ; is not repeated. I will study this deeper

Martin

Once..begin sometimes triggered twice [SOLVED]

Once..begin sometimes triggered twice

Re: Once..begin sometimes triggered twice

Re: Once..begin sometimes triggered twice

Re: Once..begin sometimes triggered twice

Once Begin: Executed twice... Any reason

Re: Once..begin sometimes triggered twice

Re: Once Begin: Executed twice... Any reason [SOLVED]

Re: Once Begin: Executed twice... Any reason

Re: Once Begin: Executed twice... Any reason

Re: Once Begin: Executed twice... Any reason