peak fitting #68

Merged
usov_i merged 6 commits from JakHolzer-fit_peak into det1d 2020-09-15 14:23:49 +02:00

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pyzebra/fit2.py Normal file
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import numpy as np
from lmfit import Model, Parameters
from scipy import integrate
from scipy.integrate import simps
def find_nearest(array, value):
array = np.asarray(array)
idx = (np.abs(array - value)).argmin()
return idx
def fitccl(
data, keys, guess, vary, constraints_min, constraints_max, numfit_min=None, numfit_max=None
):
"""Made for fitting of ccl date where 1 peak is expected. Allows for combination of gaussian, lorentzian and linear model combination
:param data: dictionary after peak fining
:param keys: name of the measurement in the data dict (i.e. M123)
:param guess: initial guess for the fitting, if none, some values are added automatically in order (see below)
:param vary: True if parameter can vary during fitting, False if it to be fixed
:param numfit_min: minimal value on x axis for numerical integration - if none is centre of gaussian minus 3 sigma
:param numfit_max: maximal value on x axis for numerical integration - if none is centre of gaussian plus 3 sigma
:param constraints_min: min constranits value for fit
:param constraints_max: max constranits value for fit
:return data dict with additional values
order for guess, vary, constraints_min, constraints_max
[Gaussian centre, Gaussian sigma, Gaussian amplitude, Lorentzian centre, Lorentzian sigma, Lorentzian amplitude, background slope, background intercept]
examples:
guess = [None, None, 100, None, None, None, 0, None]
vary = [True, True, True, True, False, True, True, True]
constraints_min = [23, None, 50, None, None, None, 0, 0]
constraints_min = [80, None, 1000, None, None, None, 0, 100]
"""
if len(data["Measurements"][str(keys)]["peak_indexes"]) != 1:
print("NO PEAK or more than 1 peak")
return
x = list(data["Measurements"][str(keys)]["omega"])
y = list(data["Measurements"][str(keys)]["counts"])
peak_index = data["Measurements"][str(keys)]["peak_indexes"]
peak_height = data["Measurements"][str(keys)]["peak_heights"]
print("before", constraints_min)
guess[0] = x[int(peak_index)] if guess[0] is None else guess[0]
guess[1] = 0.1 if guess[1] is None else guess[1]
guess[2] = float(peak_height / 10) if guess[2] is None else float(guess[2])
guess[3] = x[int(peak_index)] if guess[3] is None else guess[3]
guess[4] = 2 * guess[1] if guess[4] is None else guess[4]
guess[5] = float(peak_height / 10) if guess[5] is None else float(guess[5])
guess[6] = 0 if guess[6] is None else guess[6]
guess[7] = np.median(x) if guess[7] is None else guess[7]
constraints_min[0] = np.min(x) if constraints_min[0] is None else constraints_min[0]
constraints_min[3] = np.min(x) if constraints_min[3] is None else constraints_min[3]
constraints_max[0] = np.max(x) if constraints_max[0] is None else constraints_max[0]
constraints_max[3] = np.max(x) if constraints_max[3] is None else constraints_max[3]
print("key", keys)
print("after", constraints_min)
def find_nearest(array, value):
array = np.asarray(array)
idx = (np.abs(array - value)).argmin()
return idx
def gaussian(x, g_cen, g_width, g_amp):
"""1-d gaussian: gaussian(x, amp, cen, wid)"""
return (g_amp / (np.sqrt(2.0 * np.pi) * g_width)) * np.exp(
-((x - g_cen) ** 2) / (2 * g_width ** 2)
)
def lorentzian(x, l_cen, l_width, l_amp):
"""1d lorentzian"""
return (l_amp / (1 + ((1 * x - l_cen) / l_width) ** 2)) / (np.pi * l_width)
def background(x, slope, intercept):
"""background"""
return slope * x + intercept
mod = Model(gaussian) + Model(lorentzian) + Model(background)
params = Parameters()
params.add_many(
("g_cen", x[int(peak_index)], bool(vary[0]), np.min(x), np.max(x), None, None),
("g_width", guess[1], bool(vary[1]), constraints_min[1], constraints_max[1], None, None),
("g_amp", guess[2], bool(vary[2]), constraints_min[2], constraints_max[2], None, None),
("l_cen", guess[3], bool(vary[3]), np.min(x), np.max(x), None, None),
("l_width", guess[4], bool(vary[4]), constraints_min[4], constraints_max[4], None, None),
("l_amp", guess[5], bool(vary[5]), constraints_min[5], constraints_max[5], None, None),
("slope", guess[6], bool(vary[6]), constraints_min[6], constraints_max[6], None, None),
("intercept", guess[7], bool(vary[7]), constraints_min[7], constraints_max[7], None, None),
)
result = mod.fit(y, params, x=x)
print("Chi-sqr: ", result.chisqr)
comps = result.eval_components()
gauss_3sigmamin = find_nearest(
x, result.params["g_cen"].value - 3 * result.params["g_width"].value
)
gauss_3sigmamax = find_nearest(
x, result.params["g_cen"].value + 3 * result.params["g_width"].value
)
numfit_min = gauss_3sigmamin if numfit_min is None else find_nearest(x, numfit_min)
numfit_max = gauss_3sigmamax if numfit_max is None else find_nearest(x, numfit_max)
it = -1
while numfit_max == numfit_min:
it = it + 1
numfit_min = find_nearest(
x, result.params["g_cen"].value - 3 * (1 + it / 10) * result.params["g_width"].value
)
numfit_max = find_nearest(
x, result.params["g_cen"].value + 3 * (1 + it / 10) * result.params["g_width"].value
)
if x[numfit_min] < np.min(x):
numfit_min = gauss_3sigmamin
print("Minimal integration value outside of x range")
elif x[numfit_min] >= x[numfit_max]:
numfit_min = gauss_3sigmamin
print("Minimal integration value higher than maximal")
else:
pass
if x[numfit_max] > np.max(x):
numfit_max = gauss_3sigmamax
print("Maximal integration value outside of x range")
elif x[numfit_max] <= x[numfit_min]:
numfit_max = gauss_3sigmamax
print("Maximal integration value lower than minimal")
else:
pass
print(result.params["g_width"].value)
print(result.params["g_cen"].value)
num_int_area = simps(y[numfit_min:numfit_max], x[numfit_min:numfit_max])
num_int_bacground = integrate.quad(
background,
x[numfit_min],
x[numfit_max],
args=(result.params["slope"].value, result.params["intercept"].value),
)
d = {}
for pars in result.params:
d[str(pars)] = (result.params[str(pars)].value, result.params[str(pars)].vary)
d["export_fit"] = False
d["int_area"] = num_int_area
d["int_background"] = num_int_bacground
d["full_report"] = result.fit_report()
data["Measurements"][str(keys)]["fit"] = d
return data