how to plot time stamps

I have a problem while ploting time stamps I am uploading a notpad file with data file and also sharing my code. In data you can see that hours, minutes and seconds with milliseconds are mentioned I don't know any appropriate way to plot it so actually some how I combine hour, minutes and second in one coulmn for every time stamps and then I plot them. normally the values is like this 1.811262700000000e+05 which is actually (18:11:26.27) but few values are like this 1.813172200000000e+04 which is actually (18:13:01.722) so for that values I want to make them 1.8130172200000000e+05. or If any one knows better way to plot time stamps pleases guide me

Answer 1

[dpb]

Revamp your input parsing a little...

fmt=['%s %d %d %d %f %*s'];            % string type, ID, HR, MN, S.SSS, blank record
fid=fopen('rec_0.txt','r');            % open the file
c=textscan(fid,fmt,'delimiter','\n');  % read the file
t=table(datetime(2019,1,1,c{3},c{4},c{5}),categorical(c{1}),categorical(c{2}), ...
        'VariableNames',{'Time','Action','Code'});        % convert to table for convenience...

See what we gots...

>> disp(t)
            Time                Action         Code
    ____________________    _______________    ____
    01-Jan-2019 18:11:05    RECORDING_START    1   
    01-Jan-2019 18:11:26    LEVER_PRESS        3   
    01-Jan-2019 18:11:26    REWARD             4   
    01-Jan-2019 18:11:45    LEVER_PRESS        3   
    01-Jan-2019 18:11:45    REWARD             4   
    01-Jan-2019 18:12:02    LEVER_PRESS        3   
    01-Jan-2019 18:12:02    REWARD             4   
    01-Jan-2019 18:12:22    LEVER_PRESS        3   
    01-Jan-2019 18:12:22    REWARD             4   
    01-Jan-2019 18:12:43    LEVER_PRESS        3   
    01-Jan-2019 18:12:43    REWARD             4   
    01-Jan-2019 18:13:01    LEVER_PRESS        3   
    01-Jan-2019 18:13:01    REWARD             4   
    01-Jan-2019 18:13:22    LEVER_PRESS        3   
    01-Jan-2019 18:13:22    REWARD             4   
    01-Jan-2019 18:13:41    LEVER_PRESS        3   
    01-Jan-2019 18:13:41    REWARD             4   
    01-Jan-2019 18:13:59    LEVER_PRESS        3   
    01-Jan-2019 18:13:59    REWARD             4   
    01-Jan-2019 18:14:25    LEVER_PRESS        3   
    01-Jan-2019 18:14:25    REWARD             4   
    01-Jan-2019 18:14:43    LEVER_PRESS        3   
    01-Jan-2019 18:14:43    REWARD             4   
    01-Jan-2019 18:15:01    LEVER_PRESS        3   
    01-Jan-2019 18:15:01    REWARD             4   
    01-Jan-2019 18:15:18    LEVER_PRESS        3   
    01-Jan-2019 18:15:18    REWARD             4   
    01-Jan-2019 18:15:36    LEVER_PRESS        3   
    01-Jan-2019 18:15:36    REWARD             4   
    01-Jan-2019 18:15:54    LEVER_PRESS        3   
    01-Jan-2019 18:15:54    REWARD             4   
    01-Jan-2019 18:16:11    RECORDING_END      2   
>> 

The abvoe hardcodes the beginning date as ther first of current year, fix that to whatever is your acquisition date for general use.

Now you can use the plot routines that are datetime aware directly.

Of course, subtract (diff() to get durations.