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Re: Comparison of time entries
Posted:
Apr 25, 2012 11:21 AM
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"Johannes " <j.luthe@gmx.de> wrote in message <jn9132$eg6$1@newscl01ah.mathworks.com>... > "Barry Williams" <barry.r.williamsnospam@saic.com> wrote in message <jn8vnt$861$1@newscl01ah.mathworks.com>... > > "Johannes " <j.luthe@gmx.de> wrote in message <jn8tto$t29$1@newscl01ah.mathworks.com>... > > > First of all thanks for your really quick answers! > > > But I saw, that I haven't made myself clear enough and I even discovered a bad mistake in my problem described above. > > > > > > My original problem is what follows: > > > > > > start = datenum('14:32:41','hh:mm:ss') = 7.358125838078704e+005 > > > end = datenum('15:00:49','hh:mm:ss') = 7.348386255671296e+005 > > > > > > end - start = -9.739582407408161e+002 > > > > > > So I get for the later time a value that's smaller than that for the earlier time. How is that possible? > > > > Read doc datestr for permitted formats, then compare the results of using: > > datenum('14:32:41','hh:mm:ss') and datenum('14:32:41','HH:MM:SS') > > > > Your problem will also be apparent if you use datestr to reverse your original entries, e.g., datestr(7.358125838078704e+005) and datestr(7.348386255671296e+005). > > You will notice that they fall in different years because of the difficulty that Matlab has interpreting your format. > > > > As another matter, avoid using a keyword, like end, as a variable. > > > > Barry > > Thanks so much for your hints! > I tried using HH:MM:SS instead of hh:mm:ss and that works really fine. > > To your concerns about the variable "end": In my m-file I used the German word "Ende" for this. > I thought by translating this word into English you could possibly get the meaning of this variable better. Actually I didn't consider that "end" is a Matlab keyword.
No problem Johannes. Bitte schön. Your English is so good that I hadn't noticed it is not your native tongue. Come to think of it, because variable (and keyword) names are case sensitive, I guess End would work as a variable as well unless there is another reason to avoid it. Barry
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