[R] Convert a character to numeric

Richard M. Heiberger rmh @end|ng |rom temp|e@edu
Tue Apr 9 17:02:59 CEST 2019


My guess is that numbers formatted with commas are causing an unwanted coercion.
Remove the commas with gsub before converting to numeric.

> as.numeric(NA)
[1] NA
> as.numeric("1,234,567")
[1] NA
Warning message:
NAs introduced by coercion
> as.numeric(gsub(",", "", "1,234,567"))
[1] 1234567
>

On Tue, Apr 9, 2019 at 10:36 AM Alfredo Cortell
<alfredo.cortell.nicolau using gmail.com> wrote:
>
> Hi Bienvenue,
>
> I believe that your problem is that R can't translate "one" to a number,
> because it is not a number. R could translate to numeric for example this
> vector, where numbers are expressed as strings,
>
> c("1","4","7")
>
> but "one" is just letters put together, therefore R can't understand their
> meaning, and returns NA.
>
> I believe that your best shot is to go with gsub, so that you translate
> your "string letters" to "string numbers", and then you can do as.numeric
> no problem
>
> Try this
>
> vec<-c("1",NA,"one")
> num_vec<-gsub("one",1,vec)
> num_vec<-as.numeric(num_vec)
>
> Good luck,
>
> Alfredo
>
>
> El mar., 9 abr. 2019 a las 15:07, Duncan Murdoch (<murdoch.duncan using gmail.com>)
> escribió:
>
> > On 09/04/2019 7:30 a.m., Jim Lemon wrote:
> > > Hi Bienvenue,
> > > Perhaps you should ask whether you really want to "sort it out". The
> > > warning is telling you that you are converting the NA values to NA in
> > > the returned numeric vector.
> >
> > I don't think that's what it is saying.  I think it is saying that a
> > non-NA value is being converted to NA, because R can't figure out what
> > number it is.  For example,
> >
> >  > as.numeric(c("1", NA))
> > [1]  1 NA
> >  > as.numeric(c("1", NA, "one"))
> > [1]  1 NA NA
> > Warning message:
> > NAs introduced by coercion
> >
> >
> >   I can't think of anything more sensible
> > > to do with NA values. You may also have character strings that cannot
> > > be converted into numbers, which will also generate NA values.
> >
> > I think that's the only way that message will appear.
> >
> > Duncan Murdoch
> >
> >   Maybe a
> > > little example will help us to understand:
> > >
> > > charstr<-c("5","foot","2",NA,"eyes","of","blue")
> > > as.numeric(charstr)
> > > [1]  5 NA  2 NA NA NA NA
> > >
> > > Jim
> > >
> > > On Tue, Apr 9, 2019 at 9:16 PM bienvenidozoma using gmail.com
> > > <bienvenidozoma using gmail.com> wrote:
> > >>
> > >> Hi,
> > >>
> > >> I am applyin function as.numeric to a vector having many values as NA
> > >> and it is giving :
> > >> Warning message:
> > >> NAs introduced by coercion
> > >>
> > >> Can anyone help me to know how to remove this warning and sor it out?
> > >>
> > >> Thanks
> > >> Bienvenue
> > >>          [[alternative HTML version deleted]]
> > >>
> > >> ______________________________________________
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> > >
> > > ______________________________________________
> > > R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
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> > > PLEASE do read the posting guide
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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.
> >
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> 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.



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