[R] Numbers with correct significant digits

Andrew Robinson A.Robinson at ms.unimelb.edu.au
Sat Nov 18 04:33:22 CET 2006


I meant that it demonstrates that the number is not an integer to the
reader, regardless of how it is stored.  In the reporting of
measurements,

10 

is interpreted as an integer, whereas

10.

is interpreted as a real, rounded to two significant digits.

Cheers

Andrew



On Fri, Nov 17, 2006 at 09:55:24PM -0500, Gabor Grothendieck wrote:
> You must be thinking of some other language:
> 
> >is.integer(1)
> [1] FALSE
> 
> 
> On 11/17/06, Andrew Robinson <A.Robinson at ms.unimelb.edu.au> wrote:
> >Nice solution.
> >
> >I believe that showing the decimal point is correct.  It demonstrates
> >that the number is not an integer.
> >
> >Cheers
> >
> >Andrew
> >
> >On Fri, Nov 17, 2006 at 02:43:10PM -0800, RMan54 wrote:
> >>
> >> I think that I answered my own question.
> >>
> >> Since formatC is an implementation of the C-style formatting, I thought 
> >that
> >> a "#" as flag could work (for g and G conversions, trailing zeros are not
> >> removed  from  the  result  as they would otherwise be). Although not in 
> >the
> >> online help, this worked in R as follows:
> >>
> >> v  <- c(9.6996, 99.99)
> >> formatC(v, digits=3, format="g", flag="#")
> >>
> >> result:
> >>
> >> "9.70" "100."
> >>
> >> The only small annoyance is that the decimal point is always shown.
> >>
> >>
> >> RMan54 wrote:
> >> >
> >> > This, for example:
> >> >
> >> > v  <- c(9.6996, 99.99)
> >> > formatC(v, digits=3, format="g")
> >> >
> >> > shows:
> >> >
> >> > " 9.7" " 100"
> >> >
> >> > This is scientifically incorrect for the first number in the sense 
> >that I
> >> > like to show all 3 significant digits, including trailing zero's.
> >> > Is there a way that the first number would show as " 9.70"?
> >> >
> >> > By the way, can't use format() since it applies the same numbers of 
> >digits
> >> > after the decimal point for all numbers in the vector.
> >> >
> >> > Thanks,
> >> > Rene
> >> >
> >> >
> >>
> >> --
> >> View this message in context: 
> >http://www.nabble.com/Numbers-with-correct-significant-digits-tf2657246.html#a7412389
> >> Sent from the R help mailing list archive at Nabble.com.
> >>
> >> ______________________________________________
> >> R-help at stat.math.ethz.ch 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.
> >
> >--
> >Andrew Robinson
> >Department of Mathematics and Statistics            Tel: +61-3-8344-9763
> >University of Melbourne, VIC 3010 Australia         Fax: +61-3-8344-4599
> >http://www.ms.unimelb.edu.au/~andrewpr
> >http://blogs.mbs.edu/fishing-in-the-bay/
> >
> >______________________________________________
> >R-help at stat.math.ethz.ch 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.
> >

-- 
Andrew Robinson  
Department of Mathematics and Statistics            Tel: +61-3-8344-9763
University of Melbourne, VIC 3010 Australia         Fax: +61-3-8344-4599
http://www.ms.unimelb.edu.au/~andrewpr
http://blogs.mbs.edu/fishing-in-the-bay/



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