perform fast fourier transform and output the frequency with the highest magnitude

def freq_from_fft(raw_signal, sampling_rate):
    signal = np.array(raw_signal, dtype=np.float32)
    signal_fft = np.fft.rfft(signal)
    signal_fft = np.abs(signal_fft)
    freqs = np.fft.rfftfreq(signal.size, 1/sampling_rate)
    max_freq_index = np.argmax(signal_fft)
    freq = freqs[max_freq_index]
    return freq