colname refered by a variable
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 Jian
David Winsemius, MD West Hartford, CT