Pad with primitives painting during executing

ROOT
,
6

Ok, try:

void canvas()
{
   TCanvas *c;
   TPad *p1, *p2;
   TF1 *f1, *f2;
   int k = 1;

   f1 = new TF1("f1", "[0] * sin(x)", 0, 10);
   f1->SetParameter(0, k);
   f2 = new TF1("f1", "[0] * cos(x)", 0, 10);
   f2->SetParameter(0, k);

   c = new TCanvas("c", "c");
   p1 = new TPad("p1", "p1", 0.01, 0.01, 0.49, 0.99);
   p2 = new TPad("p2", "p2", 0.51, 0.01, 0.99, 0.99);

   p1->SetFrameFillColor(30);
   p2->SetFrameFillColor(29);
   p1->Draw();
   p2->Draw();
   p1->cd(); f1->Draw();
   p2->cd(); f2->Draw();

   c->Modified();
   c->Update();
   gSystem->ProcessEvents();
   getchar();
}
7

It works, but not every time.) Seems like it depends on previous session in root). So, I don’t understand what is going on).

Also, I noticed, that you remove p1->SetNumber(1) and replace c->cd(1) by p1->cd(). This two approach works different?

8

Weird, on which machine are you working ?

It is similar but you do not really need to loop on the pads using numbers in your example. So the 2nd approach is more compact.

9

ubuntu 18

10

I tried to execute several times the macro canvas.C. It always works the same way.

11

Can you try this macro?

void canvas()
{
	TCanvas *canva;
	TPad *p1, *p2;
	TList *list;
	TF1 *f1, *f2;
	int k;
	char strb[32];
	char c;

	k = 1;
 L_again:
	f1 = new TF1("f1", "[0] * sin(x)", 0, 10);
	f1->SetParameter(0, k);
	f2 = new TF1("f1", "[0] * cos(x)", 0, 10);
	f2->SetParameter(0, k);

	sprintf(strb, "%s_%d", "canva", k);
	canva = new TCanvas(strb, strb);
	sprintf(strb, "%s_%d", "pad1", k);
	p1 = new TPad(strb, strb, 0.01, 0.01, 0.49, 0.99);
	sprintf(strb, "%s_%d", "pad2", k);
	p2 = new TPad(strb, strb, 0.51, 0.01, 0.99, 0.99);
	
	p1->SetFrameFillColor(30);
	p1->SetFillColor(20);
	p2->SetFrameFillColor(31);
	p2->SetFillColor(21);
	p1->Draw();
	p2->Draw();
	p1->cd();
	f1->DrawCopy();
	delete f1;
	p2->cd();
	f2->DrawCopy();
	delete f2;

	canva->Modified();
	canva->Update();
	gSystem->ProcessEvents();
	printf("enter char\n");
	c = getchar();
	getc(stdin);
	printf("char = '%c'\n", c);
	if ('q' == c)
		return;
		/* NOTREACHED */
	k++;
	goto L_again;
}

Please, try to do the next steps several times:

  1. run root.
  2. “.L canvas.cpp”
  3. canvas()
  4. enter “q” after “enter char” command
  5. “.q”

Sometimes functions are painted on pads after the 3rd step, sometimes not. Or it’s always painted after 3rd step on you machine?

12

Yes, it is always painted for me.

13

Ok, then I don’t know what to do. Maybe, I will try to build the latest version of root.

14

May be

15

thanks for trying)

16

Try with:
gSystem->ProcessEvents(); gSystem->ProcessEvents(); gSystem->ProcessEvents(); // aller guten Dinge sind drei

17

Still doesn’t work every time. It works well 4 or 5 times in a row, and then not).

18

Try:
gSystem->Sleep(100); gSystem->ProcessEvents(); gSystem->Sleep(100); gSystem->ProcessEvents(); gSystem->Sleep(100); gSystem->ProcessEvents();

19

It really helps) 10 times in a row it works).

20

What operating system version / compiler version are you using?

21

ubuntu 18, c++ 7.5.0

22

@couet Are we again facing gVirtualX->Update(1); problems?

23

Maybe, I am not sure. It seems that was fixed 5 years ago.

24

Fixed in one place.
Maybe we now face something similar elsewhere (or the delays need to be increased).

25

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