hi mat,
you were probably staring at it too long and someone just needed to
have a fresh look at it! ;->
aren't you just mixing GeVs and MeVs? i changed k_mass to 0.49368 GeV
and then it worked.
ie. change
Double_t k_mass=493.68;
to
Double_t k_mass=0.49368; // also in GeV, just like the phi
cheers,
patrick.
On Thu, 21 Oct 1999, Matthew Martin wrote:
> Hi Rooters,
> I've been trying to get the following macro to work for sometime
> now with zero success.
>
>
>
>
>
> Double_t Open_fcn(Double_t *x, Double_t *par){
> Float_t xx =x[0];
> Double_t phi_mass=1.02;
> Double_t k_mass=493.68;
> Double_t Ek_CM,Pk_CM;
> Double_t beta;
> Double_t gamma=5.0;
> Ek_CM=phi_mass/2.0;
> Pk_CM=TMath::Sqrt( (Ek_CM*Ek_CM)-(k_mass*k_mass) );
> beta=TMath::Sqrt( 1.0-TMath::Power( gamma,-2.0 ) );
> Double_t
> f=(TMath::ATan(Pk_CM*TMath::Sin(xx)/(gamma*(Pk_CM*TMath::Cos(xx)+beta*Ek_CM))
> ) +
> TMath::ATan(Pk_CM*TMath::Sin(xx)/(gamma*(Pk_CM*TMath::Cos(xx)-beta*Ek_CM))
> ));
> return f;
> }//Open_fcn
>
>
> void draw_it()
> {
> TF1* open_dist = new TF1("open_dist",Open_fcn,0.0,3.14159,0);
> TCanvas* c1 = new TCanvas("c1","Opening angle dists",10,10,1200,950);
> c1->cd();
> open_dist->Draw();
> }
>
>
>
>
>
> I load it into memory, and then execute the
> draw_it() function, and I get the following error:
>
> Error in <TGaxis::PaintAxis>: wmin (-0.000000) == wmax (-0.000000)
> root [2] Error in <TGaxis::PaintAxis>: wmin (-0.000000) == wmax
> (-0.000000)
>
>
> how can I get it to work?
>
> cheers
>
> Mat
>
>
>
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Patrick Decowski |
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