Plot serial time data from excel file

Hello.

I am trying to plot data from excel file. Column 2 (amplitude) vs Column 1 (time). The time is in second

Each second the data is sample 200 time.

0.000 (second zero sample zero) => 0.199 (second zero to sample 199) to second 120.004 (120 second. sample 004).

I try writing a code, but I am not able to make it work.

Also, I am trying to plot the results where xlabel show that each second there are 200 samples.

I have try some codes.

% Define the sampling parameters
Fs = 200; % Sampling frequency in Hz
duration = 5.199; % Duration in seconds
t = 0:1/Fs:duration; % Time vector from 0 to 5.199 seconds

% Read data from Excel file
data = readtable('HUAM1709.041_v3.xlsx'); % Replace with your actual file name
amplitude = data.Var2; % Assuming the second column contains the amplitude data

% Ensure the time vector matches the length of the amplitude data
if length(amplitude) ~= length(t)
    error('Length of amplitude data does not match the time vector.');
end

% Plot the discrete time series data
figure;
stem(t, amplitude, 'filled'); % Use stem for discrete data representation
xlabel('Time (seconds)');
ylabel('Amplitude');
title('Discrete Time Series Data from 0 to 5.199 seconds');
grid on;

This code was thanks to Star Strider (Level 10 Mathworks)

data = readtable('HUAM1709.041_v2.xlsx')
% return
T = data{:,1};
T = seconds(data{:,1});
T.Format = 'hh:mm';
T2 = data{:,2};
figure;  % Place "figure" in this section allow to plot this data in a separate window.
plot (T,T2,'.');
title 'Accelerometer';
ylabel ('Amplitude');
xlabel ('Samples');

I am looking a plot like the attached file.

Where X axis is going from 0 to 120.

[Star Strider]

imshow(imread('NAA I Amplitude.jpg'))

●

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Answer 1

[Star Strider]

Your data does not look like the data in the image file.

I made some changes (additions) to your code to plot only the 't' and 'amplitude' values you define in your code that correspond to the 'duration' limit. I used 'data.Var1' as the time vector. I then determined the length (in seconds) of 't' and calculated the logical vector 'Lv' to select only those values of 't' that are less than 'duration'. I then used that logical vector to extract a matching length section of 'amplitude'. (I linked to the Excel file you posted in your earlier Question.)

file = websave('HUAM1709.041_v2.xlsx','https://www.mathworks.com/matlabcentral/answers/uploaded_files/1841254/HUAM1709.041_v2.xlsx')

file = '/users/mss.system.wzvhl/HUAM1709.041_v2.xlsx'

% Define the sampling parameters
Fs = 200; % Sampling frequency in Hz
duration = 5.199; % Duration in seconds
t = 0:1/Fs:duration; % Time vector from 0 to 5.199 seconds

% Read data from Excel file
% data = readtable('HUAM1709.041_v3.xlsx'); % Replace with your actual file name
data = readtable(file)

data = 24205×4 table
    Var1      Var2       Var3       Var4  
    _____    _______    _______    _______

        0    -0.0157     0.0107     0.0111
    0.001    -0.0758     0.0469     0.0666
    0.002     0.0612    -0.0408    -0.0544
    0.003     0.0336    -0.0217    -0.0299
    0.004    -0.0843     0.0514     0.0757
    0.005     0.0203    -0.0118    -0.0166
    0.006     0.0733     -0.046    -0.0622
    0.007    -0.0646       0.04     0.0563
    0.008    -0.0326     0.0207     0.0275
    0.009     0.0863    -0.0513    -0.0724
     0.01    -0.0209      0.017     0.0189
    0.011    -0.0723     0.0441     0.0642
    0.012     0.0668    -0.0397    -0.0556
    0.013     0.0312    -0.0193    -0.0294
    0.014    -0.0839     0.0517     0.0748
    0.015     0.0207    -0.0104     -0.017

amplitude = data.Var2; % Assuming the second column contains the amplitude data

% Fs_from_time_vector = 1/mean(diff(data{:,1}))

[tmin,tmax] = bounds(data{:,1})

tmin = 0

tmax = 121.0040

Lv = data.Var1 <= duration;                             % Logical Vector To Select Values Of The Time Vector ('data.Var1)' <= 'duration'
t_lim = data.Var1(Lv);                                  % Limited Time Vector
amplitude_lim = amplitude(Lv);                          % Limited 'amplitude' Vector

% Ensure the time vector matches the length of the amplitude data
% if length(amplitude) ~= length(t)
%     error('Length of amplitude data does not match the time vector.');
% end

% Plot the discrete time series data
figure;
% stem(t, amplitude, '.', 'filled'); % Use stem for discrete data representation
stem(t_lim, amplitude_lim , '.', 'filled')
xlabel('Time (seconds)');
ylabel('Amplitude');
title('Discrete Time Series Data from 0 to 5.199 seconds');
grid on;

This uses your selected values to plot the selected variables.

Plotting the other ones similarly --

for k = 1:2
    figure
    plot(t_lim, data{Lv,k+2})
    grid
    xlabel('t')
    ylabel('Variable')
    title("Column "+(k+2))
end

..

This is the best I can do with your data.

.