def calculate_pull(hist: TH1, ff: TF1) -> tuple:
"""
Calculate a pull plot between a histogram and a fitted function.
Parameters
----------
hist : TH1
ROOT TH1 histogram
ff : TF1
ROOT TF1 function used to fit.
Returns
-------
x, y : np.array, np.array
points for pull plot
"""
x, y = [], []
for n in range(1, hist.GetNbinsX() + 1):
x.append(hist.GetBinCenter(n))
if not hist.GetBinError(n):
y.append(0)
continue
y.append((hist.GetBinContent(n) - ff.Eval(hist.GetBinCenter(n))) / (
hist.GetBinError(n)))
return x, y
def _convert_tf1(root_obj: TF1) -> dict:
"""
Takes values from a fit function and puts them into an array
to be plotted.
Parameters
----------
root_obj : TF1
ROOT TF1
Returns
-------
dict
Dictionary with x, y points
"""
assert(isinstance(root_obj, TF1))
x = np.linspace(root_obj.GetXaxis().GetXmin(),
root_obj.GetXaxis().GetXmax(),
1000)
y = []
for p in x:
y.append(root_obj.Eval(p))
return {'x': x, 'y': np.array(y)}
