Questions from Beginners MQL5 MT5 MetaTrader 5 - page 781

[Vitaly Muzichenko]

Vladimir Karputov:

Whether it's handles or objects of the "Trend.mqh::CiMA" class, you still need to create them all.

How to solve the problem in my case?

The full task is to get 3 timeframes for 28 symbols in OnTick body.

Is it necessary to have handles = 28*3 ?

[Vladimir Karputov]

Vitaly Muzichenko:

How do I solve the problem in my case?

Complete problem, get 3 timeframes for 28 characters in OnTick body.

Is it to have handels = 28*3 ?

Yes, of course.

[Vitaly Muzichenko]

Vladimir Karputov:

Yes. Of course.

Bummer, of course(

Vladimir, you wrote to service-desk, because it shouldn't be like that, and it can't be, we must be doing something wrong that we need to create under a hundred handles for a simple Expert Advisor.

[[Deleted]]

Vitaly Muzichenko:

Itshouldn't be like this, and it can't be, we must be doing something wrong that we need to create under a hundred handles for a simple Expert Advisor.

What's the problem? You know what an array is, don't you? A structure?

Of course, if you create 100 variables, one for each handle... ...that would be a real bummer.

[Vitaly Muzichenko]

Alexey Kozitsyn:

What's the problem? You know what an array is, don't you? A structure?

Of course, if you create 100 variables, one for each handle... that'd be a real bummer.

Here, a structure indeed, but I can't figure out how to make one quickly, can I?

[[Deleted]]

Vitaly Muzichenko:

Here, really a structure, but I can't figure out how to put it together quickly, can I?

struct SHandle
   {
    string symbol;
    int handleM1;
    int handleM5;
    int handleM15;
   };
//---- или
struct SHandle
   {
    string symbol;
    int timeframes[3];   // Не знаю точно, можно ли так написать, если что, через ArrayResize();
   };
//--- 
SHandle _handles[28];    

It goes something like this...

[LookingFor]

Colleagues, I'm having some trouble understanding it at all

It constantly falls outside the array array out of range. I've investigated and written so many codes that I keep getting the same mistakes. Please advise me if there is a place (a branch, an article) where I can find out how to correctly make loops that won't throw me out of the array. I lose a lot of time finding a bug ... sometimes I do not understand what I've fixed and why it works.

For example, the following code,if (q1[i] > q1[i+1]) q2[i]=1;

on q1[i+1]

in the on unit are

SetIndexBuffer(2,q1,INDICATOR_CALCULATIONS);

ArraySetAsSeries(q1,true);

int OnCalculate(const int rates_total,
                const int prev_calculated,
                const int begin,
                const double &price[])
  {
  int sum,i,a ,start ;
  if (prev_calculated ==0) { start =0 ; q1[0]=q1[1];}
  else  start = prev_calculated;
  CopyBuffer(pulse_clear_Handle,0,start,rates_total,q1);
  for (i = start ; i < rates_total;i++)
  {if (q1[i] > q1[i+1]) q2[i]=1 ;
  else
  if (q1[i] < q1[i+1]) q2[i]=-1;
  else continue ;

[Artyom Trishkin]

LookingFor:

Colleagues, I'm having some trouble understanding it at all

It constantly falls outside the array array out of range. I've investigated and written so many codes that I keep getting the same mistakes. Please advise me if there is a place (a branch, an article) where I can find out how to correctly make loops that won't throw me out of the array. I lose a lot of time finding a bug ... sometimes I do not understand what I've fixed and why it works.

For example, the following code,if (q1[i] > q1[i+1]) q2[i]=1;

on q1[i+1]

on unit are

SetIndexBuffer(2,q1,INDICATOR_CALCULATIONS);

ArraySetAsSeries(q1,true);

for (i = start ; i < rates_total-1;i++)

[LookingFor]

Once again, thank you!

[LookingFor]

Colleagues, MathSum function, description here

https://www.mql5.com/ru/docs/standardlibrary/mathematics/stat/mathsubfunctions/statmathsum

is not recognized in build 1643 . Do I have to tear everything down and update it?