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, ______________________________________________ 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.