hi = load('mat/pi_505_high.mat', 't', 'V_in', 'V_out');
lo = load('mat/pi_505_low.mat', 't', 'V_in', 'V_out');

%%
run setup;

win = hann(ceil(0.1/Ts));

[tf_hi, f_hi] = tfestimate(hi.V_in, hi.V_out, win, [], [], 1/Ts);
[co_hi, ~] = mscohere(hi.V_in, hi.V_out, win, [], [], 1/Ts);

[tf_lo, f_lo] = tfestimate(lo.V_in, lo.V_out, win, [], [], 1/Ts);
[co_lo, ~] = mscohere(lo.V_in, lo.V_out, win, [], [], 1/Ts);

%%
figure;
ax1 = subplot(2, 1, 1);
hold on;
plot(f_hi, abs(tf_hi), 'DisplayName', 'high')
plot(f_lo, abs(tf_lo), 'DisplayName', 'low')
set(gca, 'Xscale', 'log'); set(gca, 'Yscale', 'log');
ylabel('Amplitude'); xlabel('Frequency [Hz]');
hold off;
legend('location', 'southwest');
ylim([0.1, 20]);

ax2 = subplot(2, 1, 2);
hold on;
plot(f_hi, 180/pi*unwrap(angle(tf_hi)))
plot(f_lo, 180/pi*unwrap(angle(tf_lo)))
set(gca, 'Xscale', 'log'); set(gca, 'Yscale', 'lin');
ylabel('Phase'); xlabel('Frequency [Hz]');
hold off;
ylim([-360, 0]);

linkaxes([ax1,ax2], 'x');
xlim([10, 5000]);