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# <examples/doc_fitting_withreport.py>
from numpy import exp, linspace, pi, random, sign, sin
from lmfit import create_params, fit_report, minimize
p_true = create_params(amp=14.0, period=5.46, shift=0.123, decay=0.032)
def residual(pars, x, data=None):
"""Model a decaying sine wave and subtract data."""
vals = pars.valuesdict()
amp = vals['amp']
per = vals['period']
shift = vals['shift']
decay = vals['decay']
if abs(shift) > pi/2:
shift = shift - sign(shift)*pi
model = amp * sin(shift + x/per) * exp(-x*x*decay*decay)
if data is None:
return model
return model - data
random.seed(0)
x = linspace(0.0, 250., 1001)
noise = random.normal(scale=0.7215, size=x.size)
data = residual(p_true, x) + noise
fit_params = create_params(amp=13, period=2, shift=0, decay=0.02)
out = minimize(residual, fit_params, args=(x,), kws={'data': data})
print(fit_report(out))
# <end examples/doc_fitting_withreport.py>
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