How to get a plot out of a .csv data from a sensor?

Hello Community,

I have a problem with creating a plot from the .csv-data which I created by a distance sensor. I want to have the measure time in the x-axis and the distance on the y-axis. Could anyone help me for coding?

Thank you for helping me.

Answer 1

[Image Analyst]

Try this:

fileName = 'Sample_0012023-11-30 15.05.48.343_A0000.csv'

fileName = 'Sample_0012023-11-30 15.05.48.343_A0000.csv'

t = readtable(fileName)

t = 30002×3 table
            Var1             Var2        Var3   
    ____________________    ______    __________

                     NaT       NaN    {' '     }
                     NaT       NaN    {0×0 char}
    30-Nov-2023 15:05:48    7.0486    {0×0 char}
    30-Nov-2023 15:05:48    7.0486    {0×0 char}
    30-Nov-2023 15:05:48    7.0486    {0×0 char}
    30-Nov-2023 15:05:48    7.0486    {0×0 char}
    30-Nov-2023 15:05:48    7.0486    {0×0 char}
    30-Nov-2023 15:05:48    7.0486    {0×0 char}
    30-Nov-2023 15:05:48    7.0486    {0×0 char}
    30-Nov-2023 15:05:48    7.0486    {0×0 char}
    30-Nov-2023 15:05:48    7.0486    {0×0 char}
    30-Nov-2023 15:05:48    7.0486    {0×0 char}
    30-Nov-2023 15:05:48    7.0486    {0×0 char}
    30-Nov-2023 15:05:48    7.0486    {0×0 char}
    30-Nov-2023 15:05:48    7.0486    {0×0 char}
    30-Nov-2023 15:05:48    7.0486    {0×0 char}

times = t.Var1;
distances = t.Var2;
plot(times, distances, 'b-');
grid on;
xlabel('Time');
ylabel('Distance');
title('Distance vs. Time');

Answer 2

[akshatsood]

Hi @Mathias Braun,

I understand that you are encountering difficulties in creating a plot from the CSV data generated by a distance sensor. To plot "time vs distance plot", please refer to the following steps

1. Load the CSV data into a "table" datatype using "readtable" function.
2. Extract the values for time and distance from the "data" table
3. Use "scatter" function to plot time vs distance

Here is the code snippet for your reference

% load CSV data to table
data = readtable("Sample_0012023-11-30 15.05.48.343_A0000.csv");

% read time and distance from the table
time = data(:,1).Var1;
distance = data(:,2).Var2;

% scatter plot for time vs distance
scatter(time, distance);

% add annotations
xlabel('Time');
ylabel('Distance');

title('Distance vs. Time');
axis tight;

Have a look at the following references for functions used and gain a better understanding

https://in.mathworks.com/help/matlab/ref/readtable.html?s_tid=doc_ta

https://in.mathworks.com/help/matlab/ref/scatter.html

https://in.mathworks.com/help/matlab/ref/table.html?s_tid=doc_ta

Please let me know if you have any further questions.

I hope this helps.

Answer 3

[Alexander]

My old-fashioned solution, not "fine arts", but works.

clear; close all;

Lines = char(zeros(30000,40)); % Could be any number as long as larger than expected and fitting in memory

LC = 1; % Loop counter

fid = fopen('Sample_0012023-11-30 15.05.48.343_A0000.csv');

Header = fgetl(fid)

DAQstart = fgetl(fid)

ColumnName = fgetl(fid)

while ~feof(fid)

Lines(LC,:) = fgets(fid);

LC = LC + 1;

end

fclose(fid);

Data = str2double(string(char(Lines(:,31:end)))); % The meassured data

D = Lines(:,1:19); % The Date

FS = str2double(string(Lines(:,20:26)))/24/60/60; % Fractions of Seconds

Tnum = datenum(D(1:end,:),'yyyy-mm-dd HH:MM:SS')+FS; % The date in numbers

Tstart = (Tnum - Tnum(1))*24*60*60; % The timeline beginning at 0

%plot(Tnum, Data)

plot(Tstart, Data); xlabel('t [s]'); ylabel('Distance'); title(DAQstart)

Answer 4

[Mathias Braun]

Thank you guys for these great answers ;) I really appreciate your help.