Hello, I tried to use a variable to refer colname, but I got error, could anyone give me advice?>df=data.frame(cbind(AB=1:3,AC=3:5)) > df$AC[1] 3 4 5> df$paste("A","C",sep="")Error: attempt to apply non-function thanks Jian [[alternative HTML version deleted]]
try this ..
df[,colnames(df)==paste("A","C",sep="")]
On Fri, Dec 3, 2010 at 12:05 PM, Yuan Jian <jayuan2008 at yahoo.com>
wrote:> Hello,
>
> I tried to use a?variable to refer colname, but I got error, could anyone
give me advice?
>
>>df=data.frame(cbind(AB=1:3,AC=3:5))
>> df$AC
> [1] 3 4 5
>> df$paste("A","C",sep="")
> Error: attempt to apply non-function
>
> thanks
> Jian
>
>
>
>
> ? ? ? ?[[alternative HTML version deleted]]
>
>
> ______________________________________________
> R-help at 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.
>
>
or even shorter
df[,paste("A","C",sep="")]
"Santosh Srinivas" <santosh.srinivas at gmail.com> wrote in
message
news:AANLkTikcJy7BVyfBwUwmRQ4dHg4pBdau+Qh_7+K+bRt2 at mail.gmail.com...
try this ..
df[,colnames(df)==paste("A","C",sep="")]
On Fri, Dec 3, 2010 at 12:05 PM, Yuan Jian <jayuan2008 at yahoo.com>
wrote:> Hello,
>
> I tried to use a variable to refer colname, but I got error, could anyone
> give me advice?
>
>>df=data.frame(cbind(AB=1:3,AC=3:5))
>> df$AC
> [1] 3 4 5
>> df$paste("A","C",sep="")
> Error: attempt to apply non-function
>
> thanks
> Jian
>
>
>
>
> [[alternative HTML version deleted]]
>
>
> ______________________________________________
> R-help at 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.
>
>
On Dec 3, 2010, at 4:14 AM, Keith Jewell wrote:> or even shorter > df[,paste("A","C",sep="")]Other grepping methods that generalize better to partial matches: df[ , grep("^AC$", colnames(df))] df[ grep("^AC$", colnames(df)) ] -- David.> > > "Santosh Srinivas" <santosh.srinivas at gmail.com> wrote in message > news:AANLkTikcJy7BVyfBwUwmRQ4dHg4pBdau+Qh_7+K+bRt2 at mail.gmail.com... > try this .. > > df[,colnames(df)==paste("A","C",sep="")] > > On Fri, Dec 3, 2010 at 12:05 PM, Yuan Jian <jayuan2008 at yahoo.com> > wrote: >> Hello, >> >> I tried to use a variable to refer colname, but I got error, could >> anyone >> give me advice? >> >>> df=data.frame(cbind(AB=1:3,AC=3:5)) >>> df$AC >> [1] 3 4 5 >>> df$paste("A","C",sep="") >> Error: attempt to apply non-function >> >> thanks >> JianDavid Winsemius, MD West Hartford, CT