Linking [cling interface function]

ROOT
1

I’m not good at English, so I’m sorry if the sentences are strange.
I got an error when I tried to execute the following source code.

 {
   int n=100;
   double b[10];
   double pi;
double cnt = 0.0;
 double sum=0;
 gRandom->SetSeed();
 for(int a=0.0;a<n;a++){
   double N=1000.0*(a+1.0);
   for (int j=0;j<10.0;j++){
 for (int i = 0.0; i < N; i++) {
   double x = gRandom->Rndm();
   double y = gRandom->Rndm();

		if ((x * x + y * y) < 1.0) {
			cnt +=1.0;
		}
	}
 pi = 4.0*cnt/N;
 sum+=pi;
 b[j]=pi;
   }
   double mean=pi/10;
   double sum11 = 0.0000;
   for (int j = 0; j < 10; i++)sum11 += (b[j] - mean)*(b[j]-mean);

   double sd = sqrt(sum11 / (10 - 1) / 10);

   	TGraphErrors* g = new TGraphErrors;
        g->SetPointError(a, 0, sd);  
	g->SetPoint(a, N, mean);

	g->SetMarkerStyle(20);
	g->Draw("AP");
 }

return 0;
}

I got the following error when using this source code.
IncrementalExecutor::executeFunction: symbol '_ZN5cling7runtime8internal9EvaluateTIvEET_PNS1_15DynamicExprInfoEPN5clang11DeclContextE' unresolved while linking [cling interface function]!
You are probably missing the definition of void cling::runtime::internal::EvaluateT<void>(cling::runtime::internal::DynamicExprInfo*, clang::DeclContext*)
Maybe you need to load the corresponding shared library?

Why do I get such an error?

2

At least:
for (int j = 0; j < 10; j++) sum11 += (b[j] - mean)*(b[j]-mean);

3

I have reindent you macro and it looks as follow:

{
   int n=100;
   double b[10];
   double pi;
   double cnt = 0.0;
   double sum=0;
   int j,i;
   gRandom->SetSeed();
   for(int a=0; a<n; a++){
      double N=1000.0*(a+1.0);
      for (j=0; j<10; j++) {
         for (i=0; i<(int)N; i++) {
            double x = gRandom->Rndm();
            double y = gRandom->Rndm();
            if ((x * x + y * y) < 1.0) cnt +=1.0;
         }
         pi = 4.0*cnt/N;
         sum+=pi;
         b[j]=pi;
      }
      double mean=pi/10;
      double sum11 = 0.0000;
      for (j = 0; j < 10; i++) sum11 += (b[j] - mean)*(b[j]-mean);

      double sd = sqrt(sum11 / (10 - 1) / 10);

      TGraphErrors* g = new TGraphErrors;
      g->SetPointError(a, 0, sd);
      g->SetPoint(a, N, mean);

      g->SetMarkerStyle(20);
      g->Draw("AP");
   }
}

I get no error but it seems to be in some endless loop.

4

It was a rudimentary mistake. I feel bad. I got another error when I corrected the pointed out part. I’m assuming you should see 200 plots on the graph, but only one.
If you have time, I would appreciate it if you could reply.

Info in TCanvas::MakeDefCanvas: created default TCanvas with name c1

5

Thank you!
There was no error with this.
However, the expected graph displayed 100 points with errors, but only one point is displayed. I should have looped 100 times with the for loop, why?

6

Move:
TGraphErrors* g = new TGraphErrors;
to right before:
for(int a=0.0;a<n;a++){
and move:
g->SetMarkerStyle(20); g->Draw("AP");
to right before:
return 0;

7

Can you post the corrected version of your macro ?

8

I did it well! thank you very much! !!

9

solved. I’m sorry for making a noise.
I’m really thankful to you!

10

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