Hello all,
what is the default coordinate range. In this example non is defined.
This
usually results in a plot drawn anywhere but not in the visible area.
Stephan Heising
>>>>>>>>>>>>>>>>>> Ursprüngliche Nachricht <<<<<<<<<<<<<<<<<<
Am 12/10/99, 9:12:25 AM, schrieb Rene Brun <Rene.Brun@cern.ch> zum Thema
Re: C++ code:
> Hi Anton,
> I have no problems in running your code. It is difficult to come
> with a diagnostic without more info on your error.
> I take this opportunity to AGAIN AND AGAIN request that the Root
version
> number and the machine type be always specified in the mails to
> roottalk.
> In attachment, you will find two files:
> ring.cxx to be compiled
> aring.C an interactive macro
> these files are adaptations of your example and run without problems.
> Rene Brun
> Anton V. Bogomyagkov wrote:
> >
> > Hello,
> > I wrote a C++ code for drawing a function. I can compile it, but when
I
> > try to execute the program error appears on the line where I define a
> > pointer to a TF1 class. However, canvas is drawing and function not.
Below
> > is a code of my program. So, can somebody of you help me and explain
what
> > is wrong there?
> > Thank you.
> >
> > #include <stdio.h>
> > #include <math.h>
> > #include "TROOT.h"
> > //#include "TClass.h"
> > //#include "TClassTable.h"
> > //#include "TCollection.h"
> > //#include "TObject.h"
> > #include "TCanvas.h"
> > #include "TMath.h"
> > #include "TF1.h"
> > #include "TApplication.h"
> >
> > extern void InitGui();
> > VoidFuncPtr_t initfuncs[]={InitGui, 0};
> > int Error; //needed by Motif
> >
> > TROOT root("hello","Hello World",initfuncs);
> >
> > Double_t ring(Double_t *x, Double_t *p)
> > {
> > Double_t Pi=3.14, Dl=0.005;
> > Double_t f=0, fx, phi,y,z;
> > if(p[2]){
> > for(y=p[2];y<=p[3];y+=Dl){
> > z=(x[0]-y)/p[1];
> > fx=exp(-0.5*z*z)*sqrt(p[3]*p[3]-y*y);
> > f+=p[0]*fx*Dl;
> > }
> >
> > for(y=-p[3];y<=-p[2];y+=Dl){
> > z=(x[0]-y)/p[1];
> > fx=exp(-0.5*z*z)*sqrt(p[3]*p[3]-y*y);
> > f+=p[0]*fx*Dl;
> > }
> >
> > for(y=-p[2];y<=p[2];y+=Dl){
> > z=(x[0]-y)/p[1];
> > fx=exp(-0.5*z*z)*(sqrt(p[3]*p[3]-y*y)-sqrt(p[2]*p[2]-y*y));
> > f+=p[0]*fx*Dl;
> > }
> > }
> > return f;
> > }
> >
> > int main(int argc, char **argv){
> >
> > TApplication theApp("App",&argc,argv);
> >
> > TCanvas *c1 = new TCanvas("c1","Function draw",10,10,600,450);
> > c1->Show();
> >
> > TF1 *func = new TF1("ring",ring,-6,6,4);
> > func->SetParameters(1500,0.3,1.7,1.71);
> > func->Draw();
> > c1->Update();
> >
> > theApp.Run(kTRUE);
> >
> > theApp.Run();
> >
> > return 0;
> > }
> > áÎÔÏÎ.
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