[R] string/character to number
I did a very quick search of the archive and couldn't find a readily
available answer to this one:
I'd like to convert, for example:
c("a", "b", "a", "b")
to
c(1, -1, 1, -1)
In the case of the first vector, it may be any length, but will always
only have two unique values. It must always be replaced by
corresponding values of 1 and -1.
Any thoughts?
Thanks in advance,
Jake
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Re: [R] string/character to number
Duh!
sub()
--Jake
On Jun 22, 2005, at 3:35 PM, Jake Michaelson wrote:
> I did a very quick search of the archive and couldn't find a readily
> available answer to this one:
>
> I'd like to convert, for example:
>
> c("a", "b", "a", "b")
>
> to
>
> c(1, -1, 1, -1)
>
> In the case of the first vector, it may be any length, but will always
> only have two unique values. It must always be replaced by
> corresponding values of 1 and -1.
>
> Any thoughts?
>
> Thanks in advance,
>
> Jake
>
> __
> R-help@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
>
__
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Re: [R] string/character to number
This works
x<-c("a", "b", "a", "b")
x[x=="a"]<-1
x[x=="b"]<- -1
as.numeric(x)
[1] 1 -1 1 -1
Fra: [EMAIL PROTECTED] på vegne af Jake Michaelson
Sendt: on 22-06-2005 23:35
Til: R-help@stat.math.ethz.ch
Emne: [R] string/character to number
I did a very quick search of the archive and couldn't find a readily
available answer to this one:
I'd like to convert, for example:
c("a", "b", "a", "b")
to
c(1, -1, 1, -1)
In the case of the first vector, it may be any length, but will always
only have two unique values. It must always be replaced by
corresponding values of 1 and -1.
Any thoughts?
Thanks in advance,
Jake
__
R-help@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
__
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Re: [R] string/character to number
Note: sub() returns a character vector not a numeric vector. as.numeric()
will convert it.
Slightly slicker and faster is: 2*(z=='a')-1 where z is your vector,
c('a','b','a','b')
Cheers,
Bert
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Jake Michaelson
Sent: Wednesday, June 22, 2005 2:46 PM
To: Jake Michaelson
Cc: R-help@stat.math.ethz.ch
Subject: Re: [R] string/character to number
Duh!
sub()
--Jake
On Jun 22, 2005, at 3:35 PM, Jake Michaelson wrote:
> I did a very quick search of the archive and couldn't find a readily
> available answer to this one:
>
> I'd like to convert, for example:
>
> c("a", "b", "a", "b")
>
> to
>
> c(1, -1, 1, -1)
>
> In the case of the first vector, it may be any length, but will always
> only have two unique values. It must always be replaced by
> corresponding values of 1 and -1.
>
> Any thoughts?
>
> Thanks in advance,
>
> Jake
>
> __
> R-help@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
>
__
R-help@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
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Re: [R] string/character to number
To do this in one step, it would be easier to use ifelse():
> Chars
[1] "a" "b" "a" "b"
> ifelse(Chars == "a", 1, -1)
[1] 1 -1 1 -1
HTH,
Marc Schwartz
On Wed, 2005-06-22 at 15:46 -0600, Jake Michaelson wrote:
> Duh!
>
> sub()
>
> --Jake
>
> On Jun 22, 2005, at 3:35 PM, Jake Michaelson wrote:
>
> > I did a very quick search of the archive and couldn't find a readily
> > available answer to this one:
> >
> > I'd like to convert, for example:
> >
> > c("a", "b", "a", "b")
> >
> > to
> >
> > c(1, -1, 1, -1)
> >
> > In the case of the first vector, it may be any length, but will always
> > only have two unique values. It must always be replaced by
> > corresponding values of 1 and -1.
> >
> > Any thoughts?
> >
> > Thanks in advance,
> >
> > Jake
> >
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Re: [R] string/character to number
You can do indexing by name:
> x <- c("a", "b", "a", "b")
> v <- c(a=1, b=-1)
> v[x]
a b a b
1 -1 1 -1
Andy
> From: Jake Michaelson
>
> Duh!
>
> sub()
>
> --Jake
>
> On Jun 22, 2005, at 3:35 PM, Jake Michaelson wrote:
>
> > I did a very quick search of the archive and couldn't find a readily
> > available answer to this one:
> >
> > I'd like to convert, for example:
> >
> > c("a", "b", "a", "b")
> >
> > to
> >
> > c(1, -1, 1, -1)
> >
> > In the case of the first vector, it may be any length, but
> will always
> > only have two unique values. It must always be replaced by
> > corresponding values of 1 and -1.
> >
> > Any thoughts?
> >
> > Thanks in advance,
> >
> > Jake
> >
> > __
> > R-help@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
> >
>
> __
> R-help@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
>
>
>
__
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