example of my older astropy dual peak fitting class

example_dual_peak_astropy_model.py

# Define custom two peak Gaussian model using Astropy class type.
class Gaussian1D_OIII(Fittable1DModel):
    amplitude = Parameter()
    mean = Parameter()
    stddev = Parameter()
    a = Parameter()
    b = Parameter()
    
    # evaluate the model. This is composued using the Fittable1DModel class from Astropy.
    @staticmethod
    def evaluate(x, amplitude, mean, stddev, a, b):
        model = a + b*x + np.abs(amplitude) * np.exp(- 0.5 * (x - mean) ** 2 / (np.sqrt((stddev)**2. + 1.16**2.)) ** 2) + np.abs(amplitude)/3 * np.exp(- 0.5 * (x - (mean - 47.9399)) ** 2 / (np.sqrt((stddev)**2. + 1.16**2.)) ** 2)
        return model


#%%
# single gaussian plotted at lambda_max position.
# Fit the data using a Gaussian

# curve fit attempt
g_init = Gaussian1D_OIII(amplitude=max(flux_density), mean=5045, stddev=3.0, a=0., b=0.)#, fixed={"stddev":True})
fitter = fitting.LevMarLSQFitter()
g_fit = fitter(g_init, wavelength, flux_density, maxiter=1000000000)