% Matlab Init                                              :noexport:ignore:

clear; close all; clc;

%% Intialize Laplace variable
s = zpk('s');

%% Initialize ans with org-babel
ans = 0;

% Load data
% We load the data of the z axis of two geophones.

meas14 = load('mat/data_014.mat', 'data'); meas14 = meas14.data;
meas15 = load('mat/data_015.mat', 'data'); meas15 = meas15.data;

% Time Domain
% The signals are shown on figure [[fig:ac_dc_option_time]].

figure;
hold on;
plot(meas14(:, 3), meas14(:, 1), 'DisplayName', 'Amp1 - AC');
plot(meas14(:, 3), meas14(:, 2), 'DisplayName', 'Amp2 - DC');
plot(meas15(:, 3), meas15(:, 1), 'DisplayName', 'Amp1 - DC');
plot(meas15(:, 3), meas15(:, 2), 'DisplayName', 'Amp2 - AC');
hold off;
legend('Location', 'bestoutside');
xlabel('Time [s]');
ylabel('Voltage [V]');
xlim([0, 100]);

% Frequency Domain
% We first compute some parameters that will be used for the PSD computation.

dt = meas14(2, 3)-meas14(1, 3);

Fs = 1/dt; % [Hz]

win = hanning(ceil(10*Fs));



% Then we compute the Power Spectral Density using =pwelch= function.

[pxamp1ac, f] = pwelch(meas14(:, 1), win, [], [], Fs);
[pxamp2dc, ~] = pwelch(meas14(:, 2), win, [], [], Fs);

[pxamp1dc, ~] = pwelch(meas15(:, 1), win, [], [], Fs);
[pxamp2ac, ~] = pwelch(meas15(:, 2), win, [], [], Fs);



% The ASD of the signals are compare on figure [[fig:ac_dc_option_asd]].

figure;
hold on;
plot(f, sqrt(pxamp1ac), 'DisplayName', 'Amp1 - AC');
plot(f, sqrt(pxamp2dc), 'DisplayName', 'Amp2 - DC');
plot(f, sqrt(pxamp1dc), 'DisplayName', 'Amp1 - DC');
plot(f, sqrt(pxamp2ac), 'DisplayName', 'Amp2 - AC');
hold off;
set(gca, 'xscale', 'log');
set(gca, 'yscale', 'log');
xlabel('Frequency [Hz]'); ylabel('ASD of the measured Voltage $\left[\frac{V}{\sqrt{Hz}}\right]$')
legend('Location', 'northeast');
xlim([0.1, 500]);