[R] Rounding behavior

[Jeff Newmiller]

Floating point numbers are approximations in base 2, so any fractions not representing such numbers may round off in unexpected directions.

sprintf( "%22.20f", 0.5 )
sprintf( "%22.20f", 0.575 )

See R FAQ 7.31.

On October 9, 2018 10:14:54 AM PDT, Ryan Derickson <rlderickson using gmail.com> wrote:
>Hello,
>
>Apologies if this is a simple misunderstanding.
>
>round((.575*100),0) gives 57
>round(57.5,0) gives 58
>
>Why?
>
>Ryan Derickson
>University of Cincinnati
>
>On Tue, Oct 9, 2018, 10:08 AM PIKAL Petr <petr.pikal using precheza.cz>
>wrote:
>
>> Hi
>>
>> You could use brute force approach. Just print out "file.names" and
>> estimate ordering vector.
>> In czech locale it is
>>
>> oo <- c(6, 11, 1, 4, 5, 2, 3, 10, 12, 9, 7, 8)
>>
>> In english locale it is different :-)
>>
>> After that
>> file.names[oo]
>>
>> should give you correct order of file names
>>
>> Cheers
>> Petr
>>
>> > -----Original Message-----
>> > From: R-help <r-help-bounces using r-project.org> On Behalf Of Ek Esawi
>> > Sent: Tuesday, October 9, 2018 3:44 PM
>> > To: r-help using r-project.org
>> > Subject: [R] Reorder file names read by list.files function
>> >
>> > Hi All--
>> >
>> > I used base R list.file function to read files from a directory.
>The
>> file names are
>> > months (April, August, etc). That's the system reads them in
>> alphabetical order.,
>> > but i want to reordered them in calendar order (January, February,
>> > ...December).. I thought i might be able to do it via RegEx or
>possibly
>> gtools
>> > package, I am wondering if there is an easier way.
>> >
>> > Thanks--EK
>> >
>> > Example
>> > path = "C:/Users/name/Downloads/MyFiles"
>> > file.names <- dir(path, pattern =".PDF")
>> >
>> > Example output
>> > Output:
>> > "February.PDF"  "January.PDF" "March.PDF"
>> > Desired output
>> > "January.PDF"  "February.PDF" "March.PDF"
>> >
>> > ______________________________________________
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>> http://www.R-project.org/posting-guide.html
>> > and provide commented, minimal, self-contained, reproducible code.
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>>
>
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>
>______________________________________________
>R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
>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.

-- 
Sent from my phone. Please excuse my brevity.