A Gaussian function with flexible offset, drift and amplitude

def gaussian(freq, freq0, sigma, amp, offset, drift):
    """
    A Gaussian function with flexible offset, drift and amplitude
    """
    with warnings.catch_warnings():
        warnings.simplefilter("ignore")
        return (amp * np.exp(- ((freq - freq0)**2) / (sigma**2) ) +
                drift * freq + offset)