from mosqito.utils import fm_sine_generator
import matplotlib.pyplot as plt
fs = 48000     # [Hz]
duration = 1
t = np.linspace(0, duration, int(fs*duration))
dB = 60        # [dB SPL]
fc = 50        # [Hz]
k = fc//2      # [Hz per unit amplitude of 'xm']
fm = 10        # [Hz]
xmod = np.sin(2*np.pi*t*fm)
y_fm, inst_freq, f_delta, m  = fm_sine_generator(xmod, fs, fc, k, dB, True)
fig, plots = plt.subplots(3, 1)
plots[0].set_title('Frequency-modulated sine wave')
plots[0].plot(t, xmod, 'C0', label='Modulating signal')
plots[0].legend(loc='upper right')
plots[0].grid()
plots[0].set_ylabel('Amplitude')
plots[0].set_xlim([0, duration])
plots[1].plot(t, y_fm, '#69c3c5', label='FM signal')
plots[1].legend(loc='upper right')
plots[1].grid()
plots[1].set_ylabel('Amplitude')
plots[1].set_xlim([0, duration])
plots[2].plot(t, inst_freq, '#7894cf', label='Inst Frequency')
plots[2].legend(loc='upper right')
plots[2].grid()
plots[2].hlines(fc, -0.1, 1.2*duration, color='k', linestyle='--')
plots[2].text(0.0025, fc*0.7, 'carrier freq $f_c$', fontsize=12)
plots[2].set_ylim([0, 1.1*(fc+k)])
plots[2].set_xlim([0, duration])
plots[2].set_ylabel('Frequency')
plots[2].set_xlabel('Time [s]')
plt.tight_layout()