Errorbars with standard deviation

How do I graph average bedtime in hours with a standard deviation error bar? I want the y axis to reflect times from 8pm to 6am. Also not sure how to scale x axis. The average bedtime was 1:37am and the std was 2.07.

[John Doe]

I have had this problem for non time data and created the below solution:

https://uk.mathworks.com/matlabcentral/answers/443603-max-median-min-phoney-box-plot

%sData Row 1 = mean 
%sData Row 2 = 3.std deviations
errorbar(1:1:7,sData(1,1:1:7),sData(2,1:1:7),'LineStyle','none','Marker','x')
    xlim([0 8])
    xticklabels({'' 'Data1' 'Data2' 'Data3' 'Data4' 'Data5' 'Data6' 'Data7' })
        xlabel('X Label')
        ylabel('Y Label')
        title('Example Plot')
    ax = gca;
    ax.YGrid = 'on'
    ax.YMinorGrid = 'on'

[Adam Danz]

How are you averaging the time and computing the std? For example, what's the average of [23:59, 12:01] ? You taking the mean of a timeseries?

"I want the y axis to reflect times"

Use a datetime axis.

https://www.mathworks.com/help/matlab/matlab_prog/plot-dates-and-durations.html

"How do I graph average bedtime in hours with a standard deviation error bar"

use errorbar()

https://www.mathworks.com/help/matlab/ref/errorbar.html

[Michael Molini]

I’m computing the mean from a time span of 21 days. The data comes from a struc called “diary”. Within this struc is an array for bedtimes (21x1) The variable is: bedtime = (diary.bedTime - floor(diary.bedTimes)).*24; avgbedtime = mean(bedtime(:)); SDbedtimr = std(bedtime.1);

[Adam Danz]

What is bedtime(:)? Is it a vector of date/times in datetime format? Is it part of a timetable?

I recommend organizing your data into a timetable and then using retime() to calculate means and standard deviations.

[Peter Perkins]

Michael, by your description you have 21 times; if that is a datetime array, it's easy to compute the mean (as a datetime) and the std dev (as a duration). But what's not clear is how many of those series you have. You mention scaling the x axis, but nothing more. I'm guessing maybe you have multiple subjects and want to plot each subject's mean with error bars.

This might be super easy if you have a timetable with all the data together, with a variable identifying which times go with which subject. Then you could use varfun, grouping by subject, to compute vectors of by-subject means and std devs, and plot them

But I think you're gonna need to provide more details.