I'm very new to curve/peak fitting, but I am trying to fit a data set with multiple separate independent peaks. I've tried something similar to the example provided by lmfit, and here's my code:
import matplotlib.pyplot as plt
from lmfit.models import GaussianModel
from numpy import loadtxt
data = loadtxt('079-55.freq')
x = data[:, 0]
y = data[:, 1]
gauss1 = GaussianModel(prefix='g1_')
pars = gauss1.make_params()
pars['g1_center'].set(4100, min=2000, max=4500)
pars['g1_amplitude'].set(170, min=10)
gauss2 = GaussianModel(prefix='g2_')
pars.update(gauss2.make_params())
pars['g2_center'].set(4900, min=4500, max=5500)
pars['g2_amplitude'].set(30, min=10)
gauss3 = GaussianModel(prefix='g3_')
pars.update(gauss3.make_params())
pars['g3_center'].set(600, min=5500, max=10000)
pars['g3_amplitude'].set(13, min=10)
mod = gauss1 + gauss2 + gauss3
init = mod.eval(pars, x=x)
plt.plot(x, init, 'k--')
out = mod.fit(y, pars, x=x)
print(out.fit_report())
plt.plot(x, out.best_fit, 'r-')
plt.plot(x, y)
plt.show()
However, the result becomes something like this:
I am very confused as to how to proceed to fit three separate peaks as shown below. I think the parameter update is for pitting multiple model into the same data set, not for separate independent peaks. I could be wrong though. Is there any suggestions?
