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% Frequency (Hz) and measured linear gain (unitless)
f = [610, 1220, 3050, 4270, 5490, 6100, 7320, 12200, 24400, 36600, 61000].';
G = [1.5, 1.48, 1.38, 1.32, 1.1, 0.98, 0.73, 0.34, 0.09, 0.04, 0.02].';

% Convert to magnitude in dB
GdB = 20*log10(G);

% Bode-style magnitude plot (frequency log scale)
figure;
semilogx(f, GdB, '-o', 'LineWidth', 1.5, 'MarkerSize', 6);
grid on;
grid minor;
xlim([min(f)*0.9, max(f)*1.1]);

xlabel('Frequency (Hz)');
ylabel('Magnitude (dB)');
title('Measured Bode Magnitude Plot');

% Optional: annotate corner-like points (e.g., where gain crosses 0 dB)
zcrossIdx = find(diff(sign(GdB))~=0, 1, 'first');
if ~isempty(zcrossIdx)
    % Linear interpolation of zero-crossing on log-frequency axis
    x1 = log10(f(zcrossIdx));   y1 = GdB(zcrossIdx);
    x2 = log10(f(zcrossIdx+1)); y2 = GdB(zcrossIdx+1);
    xz = x1 + (0 - y1)*(x2 - x1)/(y2 - y1);
    fz = 10^xz;
    hold on;
    plot(fz, 0, 'rs', 'MarkerFaceColor', 'r');
    text(fz, 0, '  0 dB crossing', 'VerticalAlignment', 'bottom');
end