Confusion manipulating timestamp and plotting

I'm having issues wtih a dataset that was generated by a collaborator and given to us. We have values like the following for time:

0.0517361112797516

0.0520833335031057

0.0524305557264597

0.0527777779498138

0.0531250001731678

0.0534722223965218

0.0538194446198759

0.0541666668432299

0.0545138890665839

0.0548611112899380

0.0552083335132920

I want to be able to plot my data by HH:MM:SS.

I've been able to convert this to a string using datestr(X, 'HH:MM:SS') -- just HH:MM:SS becasue I'm 99% sure the date is completely wrong, but maybe I should keep date because the data spans 2 or 3 days? I am having trouble plotting my results based on hours/minutes/seconds because the value returned is a char / string. I've played around with datnum and others but no luck.

Answer 1

[Jeremy]

Is each number supposed to represent a datetime as a "datenum" data type?

t = 0.0517361112797516;
d = datetime(t,'ConvertFrom','datenum')

returns

d = 
   datetime

   31-Dec--0001 01:14:30
   

And then

   ds = datestr(d,'HH:MM:SS')
   

returns

   ds =

    '01:14:30'

Is this correct?

[Jeremy]

To add, you could access the hour, minute, and second numbers individually like so:

[hr,s] = strtok(ds,':');
[min,s] = strtok(s,':');
[sec,s] = strtok(s,':');
clear s
hr = str2double(hr);
min = str2double(min);
sec = str2double(sec);

There may be a more efficient way to do this, but this is what came to mind as I was thinking about it.

[erkelly]

Thank you for your response!

Initially I converted all that data using the datestr, it can be converted directly

d = datestr(d,'mm-dd-yyyy HH:MM:SS');

ds = datetime(v2_1OD(:,1),'convertFrom', 'datenum');

plot(ds, y)

datetick('x', 'HH')

This plots everything and displays hours, but I also want it to plot absolute time rather than hours 0 4 8 12 16 20 24 for 3 separate days.

The strtok command didn't work for me, when I had [h,s]=strtok(d,':')

I did manage to get [h, m, s] = hms(ds) to work. Now I have to figure out the best way to make this absolute values and plot that. I could just convert all values to 'hours' and add them all together, and then add 24 and 48 to the 2nd and third day values. What do you think?