BufferResize and BufferSize for TimeSeries Classes - please help
Hi alltogether,
I'm grateful that there are people always who are willing to help and are giving competent answers to all my questions.
Following problem: I have an object of class CiHigh and I get unexpected values for BufferSize after having called BufferResize with different values:
...
Bobcat
Interesting question. Not sure if it's a feature or a bug. In all case the statement high.BufferResize(200) doesn't really resize the buffer.
I can only suggest you to write to ServideDesk to report this and ask their enlightenment.
Hii,
thank you again for your answer!
I will describe the problem to ServiceDesk and I let you know the answer!
Bobcat
"Happiness is only real when shared"
until now I have no answer from the ServiceDesk. But relax - this is no problem.
I think I have found the cause for the strange buffer size values. Please see the following code extract from Include/Indicators/TimeSeries.mqh:
//+------------------------------------------------------------------+ //| Set size of buffer | //+------------------------------------------------------------------+ bool CPriceSeries::BufferResize(const int size) { if(size>m_buffer_size && !CSeries::BufferResize(size)) return(false); //-- history is avalible CDoubleBuffer *buff=At(0); //--- check pointer if(buff==NULL) return(false); //-- buff.Size(size); //--- ok return(true); }
The and-Expression (marked in red letters) is the problem: in case if size <= m_buffer_size the second expression !CSeries::BufferResize(size) is never called (for compiler optimization strategy I guess). But one side-effect of CSeries::BufferResize is the modification/adaptation of the variable m_buffer_size.
Solutions:
a simple solution is to exchange the order of the both expressions:
if(!CSeries::BufferResize(size) && size>m_buffer_size) return(false);
A better solution would be:
bool bufres = CSeries::BufferResize(size); if(size>m_buffer_size && !bufres) return(false);
What do you think?
A second issue:
I wonder if the initial buffer size of the timeseries buffers is 100. And indeed it is:
In Include/Indicators/Series.mqh there is the following define statement:
#define DEFAULT_BUFFER_SIZE 100
This macro is used during creation of CiHigh Object.
I hope this will clarify some things....
Bobcat
until now I have no answer from the ServiceDesk. But relax - this is no problem.
I think I have found the cause for the strange buffer size values. Please see the following code extract from Include/Indicators/TimeSeries.mqh:
The and-Expression (marked in red letters) is the problem: in case if size <= m_buffer_size the second expression !CSeries::BufferResize(size) is never called (for compiler optimization strategy I guess). But one side-effect of CSeries::BufferResize is the modification/adaptation of the variable m_buffer_size.
Solutions:
a simple solution is to exchange the order of the both expressions:
A better solution would be:
What do you think?
If you want to use your correction, don't forget to use a copy of TimeSeries.mqh, as it can be overwritten during MT5 update.
I already read the code when your reported this problem, so I am aware of what you say now. But it's Metaquotes code for the Standard Library, so it's to them to fix it or say : not it works like intended. This is why I wrote previously : bug or feature ?
If you want to use your correction, don't forget to use a copy of TimeSeries.mqh, as it can be overwritten during MT5 update.
Yes, I see what you mean. Thank you.
Bobcat
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Hi alltogether,
I'm grateful that there are people always who are willing to help and are giving competent answers to all my questions.
Following problem: I have an object of class CiHigh and I get unexpected values for BufferSize after having called BufferResize with different values:
The output is:
Notes/Questions:
Many thanks for each answer!
Bobcat