Message-ID: <1a9457f8-6c06-4531-ae98-39d411f5d3a5@o11g2000yql.googlegroups.com>
Date: 2009-02-22T22:48:10Z
From: Tony
Subject: 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
>