def generate_dataset(Icase=1):
xmin = 20.
xmax = 230.
func = TF1('func', ftrue, xmin, xmax, 3)
func.SetParameters(0.01,1,0.2)
Cs = TCanvas('Cs', '', 10, 10, 800, 600)
func.Draw()
func.GetXaxis().SetTitle('mass [GeV]')
func.GetYaxis().SetTitle('Arbitrary Scale')
Cs.SaveAs('Cs_func.png')
Cs.SaveAs('Cs_func.pdf')
f = TFile('data_'+str(Icase)+'.root', 'recreate')
tree = TTree('nominal', '')
mtrue = array('f', [0])
mrec = array('f', [0])
tree.Branch('mtrue', mtrue, 'mtrue/F')
tree.Branch('mrec', mrec, 'mrec/F')
num = 10000
for i in range(num):
x0 = func.GetRandom(xmin, xmax)
if Icase == 1:
x = gRandom.Gaus(x0+5, 5)
elif Icase == 2:
x = gRandom.Gaus(x0+5, 10)
elif Icase == 3:
x = gRandom.Gaus(x0+5, 20)
else:
print('ERROR!!!')
break
#print(x0,x)
mtrue[0]=x0
mrec[0] = x
tree.Fill()
tree.Write()
f.Save()
return
