On 08-Oct-11 21:39:07, Duncan Murdoch wrote: > On 11-10-08 5:32 PM, Rolf Turner wrote: >> On 09/10/11 00:18, Duncan Murdoch wrote: >>> On 11-10-07 5:26 PM, Carl Witthoft wrote: >>>> Just wondering here -- I tested and found to my delight that >>>> >>>> % round(325.4,-2) >>>> [1] 300 >>>> >>>> gave me exactly what I would have expected (and wanted). >>>> Since it's not explicitly mentioned in the documentation >>>> that negative 'digits' is allowed, I just wanted to ask >>>> whether this behavior is intentional or a happy turn of >>>> events. I'm always paranoid that something not explicitly >>>> documented might disappear in future revisons. >>> >>> It is intentional, and one of the regression tests confirms >>> that it's there, so it won't disappear by mistake, and would >>> be very unlikely to disappear intentionally. >> >> Uh, wouldn't it be *nice* to mention this --- not completely >> obvious --- capability in the help file? > > If we told you all of R's secrets, we'd have to kill you. > > Duncan Murdoch
A Fortunate remark?? That being said -- if such are your intentions, then over my dead body ... Carl Witthoft's serendipitous discovery is a nice example of how secrets can be guessed by wondering "what if ... ?". So probably you don;t need to tell the secrets. Taking the "negative digits" to their logical extreme: round(654.321,2) # [1] 654.32 round(654.321,1) # [1] 654.3 round(654.321,0) # [1] 654 round(654.321,-1) # [1] 650 round(654.321,-2) # [1] 700 round(654.321,-3) # [1] 1000 round(654.321,-4) # [1] 0 which is what you'd logically expect (but is it what you would intuitively expect?). Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <ted.hard...@wlandres.net> Fax-to-email: +44 (0)870 094 0861 Date: 08-Oct-11 Time: 23:11:27 ------------------------------ XFMail ------------------------------ ______________________________________________ R-help@r-project.org 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.