I am new to python and trying to fit data using lmfit. I am following on the lmfit tutorial here: http://lmfit.github.io/lmfit-py/parameters.html and this is my code (based on the code explained in the above link):
import numpy as np
import lmfit
import matplotlib.pyplot as plt
from numpy import exp, sqrt, pi
from lmfit import minimize,Parameters,Parameter,report_fit
data=np.genfromtxt('test.txt',delimiter=',')
x=data[:,][:,0]
y=data[:,][:,1]
def fcn2fit(params,x,y):
"""model decaying sine wave, subtract data"""
S1=params['S1'].value
t0=params['t0'].value
T1=params['T1'].value
S2=params['S2'].value
T2=params['T2'].value
model = 1-(1-S1)*exp(-(x-t0)/T1)+S2*(1-exp(-(x-t0)/T2)
return model - y
params = Parameters()
params.add('S1', value=0.85, min=0.8, max=0.9)
params.add('t0', value=0.05, min=0.01, max=0.1)
params.add('T1', value=0.2, min=0.1, max=0.3)
params.add('S2', value=0.03, min=0.01, max=0.05)
params.add('T2', value=0.3, min=0.2, max=0.4)
result = minimize(fcn2fit, params, args=(x,y))
final = y + result.residual
report_fit (params)
try:
import pylab
pylab.plot(x,y, 'k+')
pylab.plot(x,final, 'r')
pylab.show()
except:
pass
Problem: it return syntax error for line return model-y
I appreciate if you could please let me to right direction.
I think there is a parenthesis problem in the previous line. This causes the return to be included in the formula. I think there's a ) missing at the end.