Re: [R] Filtering a data frame using a string for colum header
Hi Tony, I "GUESS" my.df[-"DrHorrible"] does not tell R which column "NUMBER" would like to remove. As we know, we could use my.df[-4] and it exactly tells R which column must remvoer from your data. > my.df[-4] Angel Buffy Firefly 1 7 8 9 2 8 9 9 3 6 4 10 4 9 9 10 51010 10 I may be not right. Chunhao > Date: Sun, 22 Feb 2009 14:48:10 -0800 > From: tony.bre...@googlemail.com > To: r-help@r-project.org > Subject: [R] Filtering a data frame using a string for colum header > > Hi all, > > I was just radomly playing with R and got the following error when > trying to filter a data frame using a string: > > > Angel <- c(7,8,6,9,10) > > Buffy <- c(8,9,4,9,10) > > Firefly <- c(9,9,10,10,10) > > DrHorrible <- c(10,9,9,10,10) > > my.df <- data.frame(Angel, Buffy, Firefly, DrHorrible) > > my.df["DrHorrible"] > DrHorrible > 1 10 > 2 9 > 3 9 > 4 10 > 5 10 > > my.df[-"DrHorrible"] > Error in -"DrHorrible" : invalid argument to unary operator > > > > I know how to work around this problem quite easily, I'm just curious > as to why the my.df[-"DrHorrible] statement didn't work? > > Cheers, > Tony > > OS = win XP > > sessionInfo() > R version 2.8.1 (2008-12-22) > i386-pc-mingw32 > > locale: > LC_COLLATE=English_United Kingdom.1252;LC_CTYPE=English_United Kingdom. > 1252;LC_MONETARY=English_United Kingdom. > 1252;LC_NUMERIC=C;LC_TIME=English_United Kingdom.1252 > > attached base packages: > [1] stats graphics grDevices utils datasets methods > base > > > > __ > 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. _ [[elided Hotmail spam]] [[alternative HTML version deleted]] __ 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.
Re: [R] Filtering a data frame using a string for colum header
Hi
r-help-boun...@r-project.org napsal dne 23.02.2009 03:44:41:
>
> Hi Tony,
>
> I "GUESS" my.df[-"DrHorrible"] does not tell R which column "NUMBER"
would
> like to remove.
> As we know, we could use my.df[-4] and it exactly tells R which column
must
> remvoer from your data.
>
> > my.df[-4]
> Angel Buffy Firefly
> 1 7 8 9
> 2 8 9 9
> 3 6 4 10
> 4 9 9 10
> 51010 10
>
>
> I may be not right.
It is a bit deeper than [] selection.
> -"DrHorrible"
Error in -"DrHorrible" : invalid argument to unary operator, so the error
is within selection operator [...].
If you know the name and you do not want column with this particular name
use
my.df[,!names(my.df)==("DrHorrible")]
Regards
Petr
>
>
>
> Chunhao
>
>
>
>
>
>
>
>
> > Date: Sun, 22 Feb 2009 14:48:10 -0800
> > From: tony.bre...@googlemail.com
> > To: r-help@r-project.org
> > Subject: [R] Filtering a data frame using a string for colum header
> >
> > Hi all,
> >
> > I was just radomly playing with R and got the following error when
> > trying to filter a data frame using a string:
> >
> > > Angel <- c(7,8,6,9,10)
> > > Buffy <- c(8,9,4,9,10)
> > > Firefly <- c(9,9,10,10,10)
> > > DrHorrible <- c(10,9,9,10,10)
> > > my.df <- data.frame(Angel, Buffy, Firefly, DrHorrible)
> > > my.df["DrHorrible"]
> > DrHorrible
> > 1 10
> > 2 9
> > 3 9
> > 4 10
> > 5 10
> > > my.df[-"DrHorrible"]
> > Error in -"DrHorrible" : invalid argument to unary operator
> > >
> >
> > I know how to work around this problem quite easily, I'm just curious
> > as to why the my.df[-"DrHorrible] statement didn't work?
> >
> > Cheers,
> > Tony
> >
> > OS = win XP
> > > sessionInfo()
> > R version 2.8.1 (2008-12-22)
> > i386-pc-mingw32
> >
> > locale:
> > LC_COLLATE=English_United Kingdom.1252;LC_CTYPE=English_United
Kingdom.
> > 1252;LC_MONETARY=English_United Kingdom.
> > 1252;LC_NUMERIC=C;LC_TIME=English_United Kingdom.1252
> >
> > attached base packages:
> > [1] stats graphics grDevices utils datasets methods
> > base
> > >
> >
> > __
> > 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.
>
> _
> [[elided Hotmail spam]]
>
>[[alternative HTML version deleted]]
>
> __
> 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.
__
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.
Re: [R] Filtering a data frame using a string for colum header
I would have used
1) != rather than ! ... ==
2) !(names(my.df) %in% "DrHorrible") since that handles NA names
(possible, but not easy to get) better.
and note that
3) subset(my.df, select = -DrHorrible) works.
On Mon, 23 Feb 2009, Petr PIKAL wrote:
Hi
r-help-boun...@r-project.org napsal dne 23.02.2009 03:44:41:
Hi Tony,
I "GUESS" my.df[-"DrHorrible"] does not tell R which column "NUMBER"
would
like to remove.
As we know, we could use my.df[-4] and it exactly tells R which column
must
remvoer from your data.
> my.df[-4]
Angel Buffy Firefly
1 7 8 9
2 8 9 9
3 6 4 10
4 9 9 10
51010 10
I may be not right.
It is a bit deeper than [] selection.
-"DrHorrible"
Error in -"DrHorrible" : invalid argument to unary operator, so the error
is within selection operator [...].
If you know the name and you do not want column with this particular name
use
my.df[,!names(my.df)==("DrHorrible")]
Regards
Petr
Chunhao
Date: Sun, 22 Feb 2009 14:48:10 -0800
From: tony.bre...@googlemail.com
To: r-help@r-project.org
Subject: [R] Filtering a data frame using a string for colum header
Hi all,
I was just radomly playing with R and got the following error when
trying to filter a data frame using a string:
Angel <- c(7,8,6,9,10)
Buffy <- c(8,9,4,9,10)
Firefly <- c(9,9,10,10,10)
DrHorrible <- c(10,9,9,10,10)
my.df <- data.frame(Angel, Buffy, Firefly, DrHorrible)
my.df["DrHorrible"]
DrHorrible
1 10
2 9
3 9
4 10
5 10
my.df[-"DrHorrible"]
Error in -"DrHorrible" : invalid argument to unary operator
I know how to work around this problem quite easily, I'm just curious
as to why the my.df[-"DrHorrible] statement didn't work?
Cheers,
Tony
OS = win XP
sessionInfo()
R version 2.8.1 (2008-12-22)
i386-pc-mingw32
locale:
LC_COLLATE=English_United Kingdom.1252;LC_CTYPE=English_United
Kingdom.
1252;LC_MONETARY=English_United Kingdom.
1252;LC_NUMERIC=C;LC_TIME=English_United Kingdom.1252
attached base packages:
[1] stats graphics grDevices utils datasets methods
base
__
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.
_
[[elided Hotmail spam]]
[[alternative HTML version deleted]]
__
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.
__
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.
--
Brian D. Ripley, rip...@stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UKFax: +44 1865 272595
__
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.
Re: [R] Filtering a data frame using a string for colum header
Cheers guys,
yeah, I was using this bit of code as my work around:
> filter.col <- which(names(my.df)!="DrHorrible")
> my.df[filter.col]
but you guys had better solutions :-)
Is there an R wish list somewhere? I tried google but couldn't find a
specific location, just various threads here and there. It just seems
to me that if
> my.df2["DrHorrible"]
works, then
> my.df2[-"DrHorrible"]
should work too, in the same way that my.df2[-2] would.
Thanks again, always good to learn new and better ways of doing
things,
Tony Breyal
On 23 Feb, 08:41, Prof Brian Ripley wrote:
> I would have used
>
> 1) != rather than ! ... ==
>
> 2) !(names(my.df) %in% "DrHorrible") since that handles NA names
> (possible, but not easy to get) better.
>
> and note that
>
> 3) subset(my.df, select = -DrHorrible) works.
>
>
>
> On Mon, 23 Feb 2009, Petr PIKAL wrote:
> > Hi
>
> > r-help-boun...@r-project.org napsal dne 23.02.2009 03:44:41:
>
> >> Hi Tony,
>
> >> I "GUESS" my.df[-"DrHorrible"] does not tell R which column "NUMBER"
> > would
> >> like to remove.
> >> As we know, we could use my.df[-4] and it exactly tells R which column
> > must
> >> remvoer from your data.
>
> >> > my.df[-4]
> >> Angel Buffy Firefly
> >> 1 7 8 9
> >> 2 8 9 9
> >> 3 6 4 10
> >> 4 9 9 10
> >> 5 10 10 10
>
> >> I may be not right.
>
> > It is a bit deeper than [] selection.
>
> >> -"DrHorrible"
> > Error in -"DrHorrible" : invalid argument to unary operator, so the error
> > is within selection operator [...].
>
> > If you know the name and you do not want column with this particular name
> > use
>
> > my.df[,!names(my.df)==("DrHorrible")]
>
> > Regards
> > Petr
>
> >> Chunhao
>
> >>> Date: Sun, 22 Feb 2009 14:48:10 -0800
> >>> From: tony.bre...@googlemail.com
> >>> To: r-h...@r-project.org
> >>> Subject: [R] Filtering a data frame using a string for colum header
>
> >>> Hi all,
>
> >>> I was just radomly playing with R and got the following error when
> >>> trying to filter a data frame using a string:
>
> Angel <- c(7,8,6,9,10)
> Buffy <- c(8,9,4,9,10)
> Firefly <- c(9,9,10,10,10)
> DrHorrible <- c(10,9,9,10,10)
> my.df <- data.frame(Angel, Buffy, Firefly, DrHorrible)
> my.df["DrHorrible"]
> >>> DrHorrible
> >>> 1 10
> >>> 2 9
> >>> 3 9
> >>> 4 10
> >>> 5 10
> my.df[-"DrHorrible"]
> >>> Error in -"DrHorrible" : invalid argument to unary operator
>
> >>> I know how to work around this problem quite easily, I'm just curious
> >>> as to why the my.df[-"DrHorrible] statement didn't work?
>
> >>> Cheers,
> >>> Tony
>
> >>> OS = win XP
> sessionInfo()
> >>> R version 2.8.1 (2008-12-22)
> >>> i386-pc-mingw32
>
> >>> locale:
> >>> LC_COLLATE=English_United Kingdom.1252;LC_CTYPE=English_United
> > Kingdom.
> >>> 1252;LC_MONETARY=English_United Kingdom.
> >>> 1252;LC_NUMERIC=C;LC_TIME=English_United Kingdom.1252
>
> >>> attached base packages:
> >>> [1] stats graphics grDevices utils datasets methods
> >>> base
>
> >>> __
> >>> r-h...@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.
>
> >> _
> >> [[elided Hotmail spam]]
>
> >> [[alternative HTML version deleted]]
>
> >> __
> >> r-h...@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.
>
> > __
> > r-h...@r-project.org mailing list
> >https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
>
> --
> Brian D. Ripley, rip...@stats.ox.ac.uk
> Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
> University of Oxford, Tel: +44 1865 272861 (self)
> 1 South Parks Road, +44 1865 272866 (PA)
> Oxford OX1 3TG, UK Fax: +44 1865 272595
>
> __
> r-h...@r-project.org mailing listhttps://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
__
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.
