def create_tree(fname, nentries=1000):
"""Create a file with a tree
>>> create_tree ( 'file.root' , 1000 )
"""
import ROOT, random
import ostap.io.root_file
from array import array
var0 = array('i', [0])
var1 = array('d', [0])
var2 = array('d', [0])
var3 = array('d', [0])
NV = 200
evars = [array('d', [0]) for i in range(NV)]
NM = 100
mvars = [array('d', 4 * [0]) for i in range(NM)]
from ostap.core.core import ROOTCWD
with ROOTCWD(), ROOT.TFile.Open(fname, 'new') as root_file:
root_file.cd()
tree = ROOT.TTree('S', 'tree')
tree.SetDirectory(root_file)
tree.Branch('evt', var0, 'evt/I')
tree.Branch('mass', var1, 'mass/D')
tree.Branch('pt', var2, 'pt/D')
tree.Branch('eta', var3, 'eta/D')
for i in range(1, NV):
tree.Branch("sv%d" % i, evars[i], 'sv%d/D' % i)
for i in range(1, NM):
tree.Branch("vv%d" % i, mvars[i], 'vv%d[4]/D' % i)
for i in range(nentries):
m = random.gauss(3.1, 0.015)
pt = random.uniform(0, 8)
eta = random.uniform(2, 4)
var0[0] = i
var1[0] = m
var2[0] = pt
var3[0] = eta
for j in range(NV):
evars[j] = j
for j in range(NM):
for k in range(4):
mvars[j][k] = 4 * j + k
tree.Fill()
root_file.Write()
def create_tree(fname, nentries=1000):
"""Create a file with a tree
>>> create_tree ( 'file.root' , 1000 )
"""
import ROOT, random
import ostap.io.root_file
from array import array
var1 = array('d', [0])
var2 = array('d', [0])
var3 = array('d', [0])
from ostap.core.core import ROOTCWD
with ROOTCWD(), ROOT.TFile.Open(fname, 'new') as root_file:
root_file.cd()
tree = ROOT.TTree('S', 'tree')
tree.SetDirectory(root_file)
tree.Branch('mass', var1, 'mass/D')
tree.Branch('pt', var2, 'pt/D')
tree.Branch('eta', var3, 'eta/D')
for i in range(nentries):
m = random.gauss(3.1, 0.015)
pt = random.uniform(0, 10)
eta = random.uniform(2, 5)
var1[0] = m
var2[0] = pt
var3[0] = eta
tree.Fill()
root_file.Write()