Remove columns with same value from a dataframe
问题 I've got a data frame like this one 1 1 1 K 1 K K 2 1 2 K 1 K K 3 8 3 K 1 K K 4 8 2 K 1 K K 1 1 1 K 1 K K 2 1 2 K 1 K K I want to remove all the columns with the same value, i.e K, so my result will be like this 1 1 1 1 2 1 2 1 3 8 3 1 4 8 2 1 1 1 1 1 2 1 2 1 I try to iterate in a for by columns but I didn't get anything. Any ideas? 回答1: To select columns with more than one value regardless of type: uniquelength <- sapply(d,function(x) length(unique(x))) d <- subset(d, select=uniquelength>1)