Matlab does plot datetime data (only hours) on wrong day
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I have data from two sensors that I want to plot in the same window to compare differences in my X value.
I have them both stored in tables and use the datetime "HH:mm:ss.SS" format.
sensor1.Time = ['12:41:50.00'; '12:41:51.00'; ...]
sensor1.x = [0.01; 0.02; 0.02; ...]
sensor2.Time = ['12:42:05.46'; '12:42:05.49'; ...]
sensor2.x = [0.01; 0.02; 0.01; ...]
When I plot the data using
plot(sensor1.Time, sensor1.x) it plots the data in a window and adds todays date.
However, when I plot the other table it adds a random date (here: 15.07.2022).
If I plot both using hold on; the data then looks like this which is not very helpful:
How can I fix this date error and have the data aligned on one day?
Star Strider on 17 Jul 2022
Without having the data to experiment with, my only suggestion is to plot them after converting them to duration arrays (that itself is not as straightforward as I would like it to be, especially since duration arrays are limited to one day in length) —
Time1 = datetime(2022,7,15) + minutes(0:1439).'
Data1 = sin(2*pi*(0:numel(Time1)-1)/720);
Time2 = datetime(2022,07,18) + minutes(0:1439).'
Data2 = cos(2*pi*(0:numel(Time1)-1)/720);
Time1.Format = 'HH:mm:ss';
Dur1 = duration(string(Time1)); % Convert To 'duration' Array
Time2.Format = 'HH:mm:ss';
Dur2 = duration(string(Time2)); % Convert To 'duration' Array
Your data will likely work for a duration array, however if they go for longer than one calendar day, it might be necessary to convert the time values only to datenum vectors and plot the data against that instead.
More Answers (2)
the cyclist on 17 Jul 2022
The most fundamental fix to your issue is to explicitly use the modern datetime format for your times. Then, downstream functions that use them as inputs can be manipulated to control the display output.
Also, rather than "MATLAB randomly does something for some reason", one can generally find the exact behavior in the documentation for each function.