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plot: Doesn't handle datetime at DST beginc correcly #738
Description
Details for the issue
Just found this on the Debian bug tracker
I have a sqlitefile with timestamps and some data values. When I plot the
data vs datetime with the builtin plot function, I get a weird outlier when
the datetime is 2006-03-26 02:00
A minimal example is here:
http://www.nmdb.eu/~steigies/debian/NEWK_2006_1h.sqlite
This also happens when I change the minute to other values as long as the
hour stays at two. I did not specify a timezone in the datetime, so if I understand
http://sqlite.org/lang_datefunc.html
correctly, this is taken as UTC.
March 26 was the beginning of Daylight Saving Time in
most of Europe, the hour between 2 and 3 does not exist on this day:
http://www.timeanddate.com/time/dst/2006.html
slitebrowser changes the datetime for this hour to ~ the year 2100 when
plotting the data. When I change my timezone from Europe/Berlin to
America/New_York, this glitch in the plot happens on April 2nd, the day DST
began in the USA.
I think sqlitebrowser should plot the data as given in the file, without
shifting values during DST switch to the year 2100 if I give it data in UTC.
If I specified a timezone, I do not expect the data to appear in 2100
either, mabye that data should be dropped from plotting, with a warning
given to the user instead.
thanks,
Christian
I'm still able to reproduce this with the latest version. It's also highly unlikely that this is a Linux-only bug.
Useful extra information
I'm opening this issue because:
- DB4S is crashing
- DB4S has a bug
- DB4S needs a feature
- DB4S has another problem
Activity
justinclift commentedon Aug 21, 2016
It seems like DB4S isn't handling invalid data points (eg datestamp that doesn't exist) in a good way.
Would the better approach be to ignore the invalid points + show a warning, or something else?
justinclift commentedon Aug 21, 2016
Well spotted btw. 😄
justinclift commentedon Aug 21, 2016
Useful conversation snippet from Christian (the original reporter), copied from email.
When we put time into fixing this, we should probably ask Christian (via the email in the Debian bug report) to test the fix.
Fix plotting with datetimes on x axis (sqlitebrowser#738)
Merge pull request #972 from prutz1311/master
MKleusberg commentedon May 5, 2017
Can somebody test if this is fixed by Oleg's change? Seems to work fine now for me at least.
justinclift commentedon May 5, 2017
Christian, the original reporter, tested our latest source today and confirms it's now working:
Looks good!
Thanks heaps for getting this taken care of @prutz1311, and @MKleusberg for the reminder. 😄