doc/v606/seism_8C.html

#include "TStopwatch.h"

#include "TDatime.h"

#include "TStyle.h"

#include "TH1F.h"

#include "TCanvas.h"

#include "TSystem.h"

#include "TRandom.h"

#include <stdio.h>


void seism() {


   TStopwatch sw; sw.Start();

   //set time offset

   TDatime dtime;

   gStyle->SetTimeOffset(dtime.Convert());


   TCanvas *c1 = new TCanvas("c1","Time on axis",10,10,1000,500);

   c1->SetFillColor(42);

   c1->SetFrameFillColor(33);

   c1->SetGrid();


   Float_t bintime = 1; //one bin = 1 second. change it to set the time scale

   TH1F *ht = new TH1F("ht","The ROOT seism",10,0,10*bintime);

   Float_t signal = 1000;

   ht->SetMaximum( signal);

   ht->SetMinimum(-signal);

   ht->SetStats(0);

   ht->SetLineColor(2);

   ht->GetXaxis()->SetTimeDisplay(1);

   ht->GetYaxis()->SetNdivisions(520);

   ht->Draw();


   for (Int_t i=1;i<2300;i++) {

      //======= Build a signal : noisy damped sine ======

      Float_t noise  = gRandom->Gaus(0,120);

      if (i > 700) noise += signal*sin((i-700.)*6.28/30)*exp((700.-i)/300.);

      ht->SetBinContent(i,noise);

      c1->Modified();

      c1->Update();

      gSystem->ProcessEvents(); //canvas can be edited during the loop

   }

   printf("Real Time = %8.3fs, Cpu Time = %8.3fs\n",sw.RealTime(),sw.CpuTime());

}