change data frame column name by set of values

Question

I am new in R. I have code for changing the data frame column name. But it's not working

df<-data.frame(a=c("a","b","c"),b=c(2,4,3))
temp<-data.frame()
nam<-df[1]
i<-1
while(i<=nrow(df))
{
temp[1,i]<-df[i,2]
i<-i+1
}
colnames(temp)<-nam

Expected output is

>temp
a b c
2 4 3

Answer 1

You can use unlist to transform the one-column data frame nam into a vector:

colnames(temp) <- unlist(nam)

#   a b c
# 1 2 4 3

A better way is to use [[ instead of [ when creating nam . This will create a vector, and you don't need unlist :

nam <- df[[1]]
colnames(temp) <- nam

---

By the way: You can create the new data frame based on df in an easier way (without loops):

setNames(as.data.frame(t(df[[2]])), df[[1]])
#   a b c
# 1 2 4 3

Answer 2

colnames(temp) = t(nam)

要么

names(temp) = t(nam)

Answer 3

You can change the column names with

colnames(temp) <- c("a", "b", "c")

the row names are analoguous

rownames(temp) <- c(2,4,5)