Transposing a dataframe maintaining the first column as heading

问题

I have a big dataframe, but small example would be like this:

mydf <- data.frame(A = c(letters[1:10]), M1 = c(11:20), M2 = c(31:40), M3 = c(41:50))

I want to transpose the dataframe and maintain the column 1 (A) as column heading ( letter[1:10]) as variable names. The following are scratch trials of unsuccessful codes.

tmydf = data.frame(t(mydf))
names(tmydf) <- tmydf[1,]

Thanks;

回答1:

Here is one way

tmydf = setNames(data.frame(t(mydf[,-1])), mydf[,1])

回答2:

Something like this perhaps:

tmp <- as.data.frame(t(mydf[,-1]))
> colnames(tmp) <- mydf$A
> tmp
    a  b  c  d  e  f  g  h  i  j
M1 11 12 13 14 15 16 17 18 19 20
M2 31 32 33 34 35 36 37 38 39 40
M3 41 42 43 44 45 46 47 48 49 50

回答3:

Data.table variante from Ramnath with indicating in string the variable name wanted.

mydf <- data.table(A = c(letters[1:10]), M1 = c(11:20), M2 = c(31:40), M3 = c(41:50))
tmydf <- setNames(data.table(t(mydf[,-"A"])), mydf[["A"]])

来源：https://stackoverflow.com/questions/7970179/transposing-a-dataframe-maintaining-the-first-column-as-heading