#include<sstream>
#include<iostream>

std::cerr<<"Hello World!"<<std::endl;

Hello World!

%jsroot on
TH1D *h1 = new TH1D("h1","h1",100,-5,5);
TF1 *f1 = new TF1("f1","[0]*TMath::Gaus(x,[1],[2])",-5, 5);
f1->SetParameters(1,0,1);
h1->FillRandom("f1", 1000);
TCanvas *canv = new TCanvas("canv","canv");
h1->Draw("eh");
h1->Fit(f1,"R");
canv->Draw();

****************************************
Minimizer is Minuit2 / Migrad
Chi2                      =      75.7525
NDf                       =           56
Edm                       =  2.20442e-08
NCalls                    =          143
p0                        =      39.8365   +/-   1.69128     
p1                        =   -0.0523074   +/-   0.0313946   
p2                        =    -0.929008   +/-   0.0257699

void fillrandom() {
    TCanvas *c1 = new TCanvas("c1","The FillRandom example",200,10,700,900);
    c1->Draw();
   auto pad1 = new TPad("pad1","The pad with the function",0.05,0.50,0.95,0.95);
   auto pad2 = new TPad("pad2","The pad with the histogram",0.05,0.05,0.95,0.45);
   pad1->Draw();
   pad2->Draw();
   pad1->cd();
 
   gBenchmark->Start("fillrandom");
   //
   // A function (any dimension) or a formula may reference
   // an already defined formula
   //
   auto form1 = new TFormula("form1","abs(sin(x)/x)");
   auto sqroot = new TF1("sqroot","x*gaus(0) + [3]*form1",0,10);
   sqroot->SetParameters(10,4,1,20);
   pad1->SetGridx();
   pad1->SetGridy();
   pad1->GetFrame()->SetBorderMode(-1);
   pad1->GetFrame()->SetBorderSize(5);
   sqroot->SetLineColor(4);
   sqroot->SetLineWidth(6);
   sqroot->Draw();
   auto lfunction = new TPaveLabel(5,39,9.8,46,"The sqroot function");
   lfunction->Draw();
   c1->Update();
 
   //
   // Create a one dimensional histogram (one float per bin)
   // and fill it following the distribution in function sqroot.
   //
   pad2->cd();
   pad2->GetFrame()->SetBorderMode(-1);
   pad2->GetFrame()->SetBorderSize(5);
   auto h1f = new TH1F("h1f","Test random numbers",200,0,10);
   h1f->SetFillColor(45);
   h1f->FillRandom("sqroot",10000);
   h1f->Draw();
   c1->Update();
   //
   // Open a ROOT file and save the formula, function and histogram
   //
//    TFile myfile("fillrandom.root","RECREATE");
//    form1->Write();
//    sqroot->Write();
//    h1f->Write();
    gBenchmark->Show("fillrandom");
}

%jsroot on
fillrandom();

fillrandom: Real Time =   0.02 seconds Cpu Time =   0.02 seconds

//final update
system("date '+%b %d %Y (%a)'");

12 27 2023 (水)

JupyterLabでROOTカーネルを使う¶