Dear Valery
The class defination "test.h" and its implementation "test.c" is
followed. The running is like
* aa = new test();
* aa->Draw();
In the code, the implentation "Draw()" is like:
void test::Draw()
{
fpx->Draw(); //fpx is a TH1 object
}
When running like:
aa = new test();
aa->Draw();
It will produce a Canvas with a histogram in it. After selecting the
option "Event Status" in TCanvas, I can find three objects:
c1 --> default Canvas
fpx -->the TH1 object.
TFrame --> Frame that contains the "fpx"
But can not find "aa". Deleting "aa" will have no effect on the existing
TCanvas and Histograms. It seems to say that "aa" is not in the Canvas.
Sincerely yours
Xie
********
>>test.h
********
#ifndef _test_
#define _test_
#include <stdlib.h>
#include <TROOT.h>
#include <TApplication.h>
#include <TObject.h>
#include <TCanvas.h>
#include <TH1.h>
#include <TRandom.h>
class test:public TH1 {
private:
TH1F *fHpx;
public:
test();
Int_t DistancetoPrimitive(Int_t px, Int_t py);
void ExecuteEvent(Int_t event, Int_t px, Int_t py);
void Draw();
ClassDef(test,0)
};
#endif
**********
>> test.c
*********
#include "test.h"
ClassImp(test)
test::test(): TH1()
{
static int cnt;
if (!fHpx) {
fHpx = new TH1F("hpx","",100,-4,4);
fHpx->SetFillColor(kRed);
cnt = 0;
}
int kUPDATE = 1000;
float px, py;
Int_t num=0;
while (num<1000)
{
num++;
gRandom->Rannor(px,py); //px and py will be two gaussian random numbers
fHpx->Fill(px);
}
}
Int_t test::DistancetoPrimitive(Int_t px, Int_t py)
{
return TH1::DistancetoPrimitive(px, py);
}
void test::ExecuteEvent(Int_t event, Int_t px, Int_t py)
{
Float_t x,y;
switch (event)
{
case kMouseMotion:
x = gPad->AbsPixeltoX(px);
y = gPad->AbsPixeltoY(py);
printf("x=%.3g, y=%.3g",gPad->PadtoX(x),gPad->PadtoY(y));
break;
}
}
void test::Draw()
{
fHpx->Draw();
}
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