Hello,
I had no problems, and it shouldn't. What exactly do you mean by "not
working"?
Hope this helps,
Rui Barradas
Em 04-10-2013 17:06, Jie escreveu:
Dear All,
I have a question, suppose X is a dataframe, with column names as
"x1", "x2", "x3", ..... And I would like to use the i-th column by X[,'xi'].
But it seems the single quote and double quote are different.
So if I run X[, names(X)[i]], it has some error.
Please use the below example code
X = matrix(rnorm(50),ncol = 5)
X = data.frame(X)
names(X)=c("x1","x2","x3","x4","x5")
#pick the 4-th column
X[,'x4'] #working
X[,names(X)[4]] # not working , so how to modify this line?
names(X)[4] # returns "x4"
sQuote(names(X)[4]) # returns "'x4'"
Best,
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______________________________________________
[email protected] 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.