Thank you both to Michael and Calum, Your comments pointed me to the answer.
I did not succeed in making a useful reproducible example using dput(), so I'll have to study that command further. But it is no longer necessary for this thread to have a successful end. Your comments about floating point gremlins, and the reminder that as.integer (15070.1) is 15070, made me realize that I should have used as.numeric(), not as.integer(), to see what was going on. The two dates were indeed different, one was 15070.3. I went back to the many operations I did to create the offending dataframe and realized that I aggregated two small samples together and attributed to them the mean date (literally using the mean function on the 2 dates). As the result looked normal in Date format, I thought all was well. Lesson learned. Thanks again and sorry to have been a bit quick to resort to the list on this one. Denis Le 2012-04-17 à 12:53, R. Michael Weylandt a écrit : > A slightly quieter response: > > Please use dput() to create a reproducible example -- for this case, > if x and y aren't too long, it seems that dput(x) and dput(y) would > comprise one. str() helps (and thank you for that -- it gave me a > place to start), but it doesn't provide quite enough to reproduce > here. > > My guess is that R FAQ 7.31 is in play here... note that > storage.mode(as.Date(Sys.Date())) is double not integer, so you need > to keep an eye on the floating point gremlins. > > Michael > > On Tue, Apr 17, 2012 at 12:25 PM, Calum Polwart > <[email protected]> wrote: >> >> >> On Tue, 17 Apr 2012 10:44:40 -0400, Denis Chabot wrote: >> >>> Hi, >>> >> >>> I cannot make a reproducible example easily for my problem, so I'll >>> >> describe it as best as I can. >> >> YOU KIND OF NEED ONE... >> >>>> >> a=test1$période[21] >>> >>>> b=test2$date[22] >>> a f >>> argin-left:5px; >> width:100%">b >>> >>> [1] "2011-04-06" >>> >>>> >> >> THIS IS WHY YOU NEED TO >> GIVE US A REPRODUCABLE MEANS BECAUSE IF I SIMPLY DO A="2011-04-06" AND >> B="2011-04-06" I'M GOING TO GET A==B TRUE >> >> WHERE IS THE DATA IN THE DF'S >> BEING SOURCED FROM? IS IT A DATABASE? COULD THERE BE DIFFERENT DATA >> DEFINITIONS? IS ITS A CSV FILE ETC? >> >> and then thi> ft:#1010ff 2px >> solid; margin-left:5px; width:100%">as.integer(a) >>> >>> [1] 15070 >>> >>>> >> as.integer(b) >>> >>> [1] 15070 >>> >>> SUGGESTION THAT MIGHT POINT YOU IN A >> DIRECTION... >>> >>> as.integer (15070) >> pre> >> >> as.integer (15070.1) >> >> [1] >> 15070 >> >> as.integer (15070)==as.integer(15070.1) >> >> [1] >> TRUE >> >> 15070==15070.1 >> >> [1] FALSE >> >> SECOND SUGGESTION WOULD BE TO DROP THE >> É NO IDEA WHY THAT WOULD CAUSE A PROBLEM (OR WHERE), BUT ANYTHING THATS >> NOT A-Z OR A-Z ONLY INTRODUCES A POTENTIAL EXTRA HEADACHE... >> >> >> as.integer(a)==as.integer(b) >> >>> >> >> [[alternative HTML version deleted]] >> >> >> ______________________________________________ >> [email protected] mailing list >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, reproducible code. >> ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
