Rename a single column in dataframe using R

Question

How to rename a vector/data frame with a single column?

I know with various columns, I can use

colnames(x) <- c("col1","col2")


#Consider this example
 Samp <- data.frame(sample(trainer$index, 10000))
head(Samp )
#   sample.trainer.index..10000.
# 1                      5907862
# 2                      2181266
# 3                      7368504
# 4                      1949790
# 5                      3475174
# 6                      6062879

ncol(Samp)
# [1] 1
class(Samp)
# [1] "data.frame"
class(Samp[1])
# [1] "data.frame"
class(Samp[,1])
# [1] "numeric"
colnames(Samp)[2] <- "newname2"
# Error in names(x) <- value : 
#   'names' attribute [2] must be the same length as the vector [1]

Answer 1

colnames(Samp)[2] <- "newname2"

This sets the name of second column. But since you have only one column you can use:

colnames(trSamp) <- "newname2"