Plotting with data in .mat files

Question

Shamus Sim 2020-8-9

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/577186-plotting-with-data-in-mat-files

编辑： NA 2020-8-9

HI there,

I am trying to make a simple time-series plot. My Yvalues(Voltage) are arranged in these data.mat files that traverse horizontally and then down to the next row, row by row. You can see here. data is a 16x239766 double. (You can see the lowest Screenshot)

The code I have wrote is:

load('interictal_segment_255')

%Plotting time-series for ECG data

%sampling frequency

sf=399.0698

T=1/sf

Xplot=T:T:600

plot(Xplot,interictal_segment_255.data)

The error I have gotten is:

Error using plot

Vectors must be the same length.

Also, Im trying to create a for loop to read all my data here.(See first screenshot). They are divide into Dog_1 until Dog_5. They all have the same field with the struct,interictal_segment_255. I have tried to create a for loop for this but unsucessful. Im trying to plot the time series for a particular segment when I call for it. Eg: interictal_segment_255 and get the plotted time series for the whole segment.

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Mario Malic 2020-8-9

Your Xplot is a vector with 239441 elements and needs to have the same number of columns as your data which is 239766.

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Answer 1

NA 2020-8-9

0
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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/577186-plotting-with-data-in-mat-files#answer_477148

编辑：NA 2020-8-9

在 MATLAB Online 中打开

You are getting an error because the vectors are not the same size.

You have a 16 x 239766 matrix and you want to plot it against a 1 x 239441, which is not possible because 239766 > 239441.

From your code, one can deduce that you have collected data over 600s. However, based on your sampling rate (399.0698), this time is actually slightly greater than 600s i.e. 239766 / 399.0698 = 600.8122. Which suggests that you collected data over 600.8122s rather than 600s.

By running the code below you should be able to plot your ECG data without encountering any errors:

data = rand(16, 239766); %dummy data
sf = 399.0698; %sampling frequency (Hz), samples per second
T = 1/sf;
timeSeries = T:T:600.8122;
figure;
plot(timeSeries, data);

Try this to load your files, you will likely have to adjust it based on your directory.

animalFolder = {...
    'Dog_1'...
    'Dog_2'...
    'Dog_3'...
    'Dog_4'...
    'Dog_5'...
    };
animalN = size(animalFolder, 1);
    
directory = 'C:\Users\USERS\Desktop\SHAMUS\Dr.Lan\'; %check this
ecgData = '\interictal_segment_255';
time = '\xxxxx'; %replace xxxxx with name of time-series file
for ii = 1:animalN
  
    folder = [animalFolder{ii,1} '\'];
    
    load([directory folder ecgData]); %loads ecg data for each animal
    load([directory folder time]); %loads time series for each animal
    
end