How to handle the error in MML4 and MQL5? - General

TheXpert 2019.05.22 13:42 #24681

I'll know ) then hack

Eugeni Neumoin 2019.05.22 13:50 #24682

I am transferring a program from MQL4 to MQL5.

I have faced this error.

On timeframes up to m30 the Period() value is correct.

2019.05.22 17:45:38.628 TestStat (GBPUSD,M15) 4854 Period()=15
2019.05.22 17:46:08.267 TestStat (GBPUSD,M30) 4854 Period()=30

From timeframe H1 I get incomprehensible values.

2019.05.22 17:31:07.446 TestStat (GBPUSD,H1) 4854 Period()=16385
2019.05.22 17:46:39.362 TestStat (GBPUSD,H4) 4854 Period()=16388
2019.05.22 17:46:55.552 TestStat (GBPUSD,D1) 4854 Period()=16408

Terminal version build 2057 dated 21 May 2019.

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Eugeni Neumoin 2019.05.22 13:56 #24683

Thank you.

In the description:

Period

Returns the timeframe value of the current chart.

ENUM_TIMEFRAMESPeriod();

Returned value

Contents of the _Period variable, holding the timeframe value of the current chart. Value can be one ofthe ENUM_TIMEFRAMESenumerationvalues .

=================

That's not very well done. It should be correctly written in the description. You should not look for the source of the problem on the forum.

It turns out that Period() won't give out the value of the current timeframe as it says:The value can be one of the values of enumeration ENUM_TIMEFRAMES.

But something else entirely.

Please correct the language description for developers.

Questions from Beginners MQL5 iCustom MQL5 return zero [Solved] Can i compare

Sergey Dzyublik 2019.05.22 14:01 #24684

Thanks again toTheXpert for providing the code.
We have the following results on ArrayResize capacity MT5(build 2057):

#import "msvcrt.dll"
  long memcpy(int &dst[], long &src, int cnt);
#import

#define  PRINT(x) ; Print(#x, ":", string(x))

template<typename T>
struct ArrayStore
{
   long offset;
   T x[];
   
   int capacity() 
   {
      int ints[sizeof(ArrayStore) / sizeof(int)];
      memcpy(ints, this.offset, sizeof(ArrayStore));
      return ints[8];
   }
   
   int size() 
   {
      int ints[sizeof(ArrayStore) / sizeof(int)];
      memcpy(ints, this.offset, sizeof(ArrayStore));
      return ints[4];
   }
};

template<typename T>
int TestArrayCapacity(ArrayStore<T> &store, int size, int reserved_size = 0){
   ArrayResize(store.x, size, reserved_size);
   return store.capacity(); 
}

template<typename T>
int TestArraySize(ArrayStore<T> &store, int size, int reserved_size = 0){
   ArrayResize(store.x, size, reserved_size);
   return store.size(); 
}


void OnStart()
{
   ArrayStore<int> store;
   
   PRINT("TEST_ArrayCapacity");
   
   PRINT(TestArrayCapacity(store, 100, 0)); 
   PRINT(TestArrayCapacity(store, 100, 100)); 
   PRINT(TestArrayCapacity(store, 101, 100)); 
   PRINT(TestArrayCapacity(store, 200, 100)); 
   PRINT(TestArrayCapacity(store, 201, 100)); 
   PRINT(TestArrayCapacity(store, 202, 100)); 
   PRINT(TestArrayCapacity(store, 100,   1)); 
   PRINT(TestArrayCapacity(store, 100, 400)); 
   PRINT(TestArrayCapacity(store, 300, 400)); 
   PRINT(TestArrayCapacity(store, 301, 600));
   PRINT(TestArrayCapacity(store, 302, 600));
   PRINT(TestArrayCapacity(store, 303, 600));
   PRINT(TestArrayCapacity(store, 100,   0)); 
   PRINT(TestArrayCapacity(store, 100, 100)); 
   PRINT(TestArrayCapacity(store, 100,  -1)); 
   PRINT(TestArrayCapacity(store, 100, 100)); 
   PRINT(TestArrayCapacity(store, 105, 100)); 
}

Result:

2019.05.22 17:00:50.249 Test_array_resize (EURUSD,H1)   TEST_ArrayCapacity:TEST_ArrayCapacity
2019.05.22 17:00:50.249 Test_array_resize (EURUSD,H1)   TestArrayCapacity(store,100,0):100
2019.05.22 17:00:50.249 Test_array_resize (EURUSD,H1)   TestArrayCapacity(store,100,100):100
2019.05.22 17:00:50.249 Test_array_resize (EURUSD,H1)   TestArrayCapacity(store,101,100):201
2019.05.22 17:00:50.249 Test_array_resize (EURUSD,H1)   TestArrayCapacity(store,200,100):201
2019.05.22 17:00:50.249 Test_array_resize (EURUSD,H1)   TestArrayCapacity(store,201,100):201
2019.05.22 17:00:50.249 Test_array_resize (EURUSD,H1)   TestArrayCapacity(store,202,100):302
2019.05.22 17:00:50.249 Test_array_resize (EURUSD,H1)   TestArrayCapacity(store,100,1):302
2019.05.22 17:00:50.249 Test_array_resize (EURUSD,H1)   TestArrayCapacity(store,100,400):302
2019.05.22 17:00:50.249 Test_array_resize (EURUSD,H1)   TestArrayCapacity(store,300,400):302
2019.05.22 17:00:50.249 Test_array_resize (EURUSD,H1)   TestArrayCapacity(store,301,600):302
2019.05.22 17:00:50.249 Test_array_resize (EURUSD,H1)   TestArrayCapacity(store,302,600):302
2019.05.22 17:00:50.249 Test_array_resize (EURUSD,H1)   TestArrayCapacity(store,303,600):903
2019.05.22 17:00:50.249 Test_array_resize (EURUSD,H1)   TestArrayCapacity(store,100,0):903
2019.05.22 17:00:50.249 Test_array_resize (EURUSD,H1)   TestArrayCapacity(store,100,100):903
2019.05.22 17:00:50.250 Test_array_resize (EURUSD,H1)   TestArrayCapacity(store,100,-1):100
2019.05.22 17:00:50.250 Test_array_resize (EURUSD,H1)   TestArrayCapacity(store,100,100):100
2019.05.22 17:00:50.250 Test_array_resize (EURUSD,H1)   TestArrayCapacity(store,105,100):205

Igor Zakharov 2019.05.22 14:05 #24685

Eugeni Neumoin:

Description:

Contents of the _Period variable, which stores the timeframe value of the current chart. The value can be one of the values of ENUM_TIMEFRAMESenumeration.

This is not done well. It should be correctly written in the description. You should not look for the source of the problem on the forum.

So nowhere is it written that this value equals the period in minutes (as it was in quad).

https://www.mql5.com/ru/articles/81

That's where the link article starts.

Переход с MQL4 на MQL5

www.mql5.com

Данная статья, построенная в форме справочника по функциям MQL4, призвана помочь переходу с MQL4 на MQL5. Для каждой функции языка MQL4 приведено описание и представлен способ ее реализации на MQL5, что позволит вам значительно ускорить перевод своих программ с MQL4 на MQL5. Для удобства функции разбиты на группы, как в документации по MQL4.

Eugeni Neumoin 2019.05.22 14:11 #24686

Igor Zakharov:

So nowhere does it say that this value is equal to the period in minutes (as it was in fours).

https://www.mql5.com/ru/articles/81

This is where the article on the link starts.

There is a description of the language that says: Value can be one of the values of ENUM_TIMEFRAMESenumeration.

See the language description further down:

Graph periods

All predefined chart periods have unique identifiers. The PERIOD_CURRENT identifier means the current period of the chart, at which the mql5 program is running.

ENUM_TIMEFRAMES

Identifier	Description
PERIOD_CURRENT	Current period
PERIOD_M1	1 minute
PERIOD_M2	2 minutes
PERIOD_M3	3 minutes
PERIOD_M4	4 minutes
PERIOD_M5	5 minutes
PERIOD_M6	6 minutes
PERIOD_M10	10 minutes
PERIOD_M12	12 minutes
PERIOD_M15	15 minutes
PERIOD_M20	20 minutes
PERIOD_M30	30 minutes
PERIOD_H1	1 hour
PERIOD_H2	2 hours
PERIOD_H3	3 hours
PERIOD_H4	4 hours
PERIOD_H6	6 hours
PERIOD_H8	8 hours
PERIOD_H12	12 hours
PERIOD_D1	1 day
PERIOD_W1	1 week
PERIOD_MN1	1 month

======================

And nowhere in the description does it say that this value is in seconds.

The description should say it all.

And when you have to look up some other articles, that's too bad.

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Sergey Dzyublik 2019.05.22 14:14 #24687

Sergey Dzyublik:
Thanks again toTheXpert for providing the code.
We have the following results on ArrayResize capacity MT5(build 2057):

So, conclusions on ArrayResize performance and impact on real capacity:

1. The first ArrayResize is very important, it really allocates memory taking into account size + reserved_size and sets capacity.
2. All subsequent ArrayResize executions with a new value of reserved_size have no effect on the amount of allocated memory and capacity, respectively.
3 New memory allocation is performed only when capacity is exceeded and in this case size + reserved_size is used again to determine the amount of allocated memory and set a new capacity.
4. A value of reserved_size < 0 releases the reserved memory to size size.

Any rookie question, so ArrayResize need any control Array out of range

Igor Zakharov 2019.05.22 14:16 #24688

Eugeni Neumoin:

And nowhere in the description does it say that this value is in seconds.

So it's not in seconds...

Alexey Viktorov 2019.05.22 14:17 #24689

Eugeni Neumoin:

There is a language description that says: Value can be one of the ENUM_TIMEFRAMESenumeration values .

See further in the language description:

Graph periods

All predefined chart periods have unique identifiers. The PERIOD_CURRENT identifier means the current period of the chart, at which the mql5 program is running.

ENUM_TIMEFRAMES

======================

And nowhere in the description does it say that this value is in seconds.

The description should say it all.

And when you have to go through some other articles, it's too bad.

Who told you that these are values in seconds?

Alain Verleyen 2019.05.22 14:24 #24690

Eugeni Neumoin :

There is a language description that says: Value can be one of the values of enumeration ENUM_TIMEFRAMES.

See further in the language description:

Graph periods

All predefined chart periods have unique identifiers. The PERIOD_CURRENT identifier denotes the current period of the chart, at which the mql5 program is running.

ENUM_TIMEFRAMES

Identifier	Description
PERIOD_CURRENT	Current period
PERIOD_M1	1 minute
PERIOD_M2	2 minutes
PERIOD_M3	3 minutes
PERIOD_M4	4 minutes
PERIOD_M5	5 minutes
PERIOD_M6	6 minutes
PERIOD_M10	10 minutes
PERIOD_M12	12 minutes
PERIOD_M15	15 minutes
PERIOD_M20	20 minutes
PERIOD_M30	30 minutes
PERIOD_H1	1 hour
PERIOD_H2	2 hours
PERIOD_H3	3 hours
PERIOD_H4	4 hours
PERIOD_H6	6 hours
PERIOD_H8	8 hours
PERIOD_H12	12 hours
PERIOD_D1	1 day
PERIOD_W1	1 week
PERIOD_MN1	1 month

======================

And nowhere in the description does it say that this value is in seconds.

The description should say it all.

And when you have to go through some other articles, that's too bad.

You should never rely on an enumeration value.

Use PeriodSeconds().

Errors, bugs, questions - page 2469