问题
What is the best way to transpose a data.frame in R and to set one of the columns to be the header for the new transposed table? I have coded up a way to do this below. As I am still new to R. I would like suggestions to improve my code as well as alternatives that would be more R-like. My solution is also unfortunately a bit hard coded (i.e. the new column headings are in a certain location).
# Assume a data.frame called fooData
# Assume the column is the first column before transposing
# Transpose table
fooData.T <- t(fooData)
# Set the column headings
colnames(fooData.T) <- test[1,]
# Get rid of the column heading row
fooData.T <- fooData.T[2:nrow(fooData.T), ]
#fooData.T now contains a transposed table with the first column as headings
回答1:
Well you could do it in 2 steps by using
# Transpose table YOU WANT
fooData.T <- t(fooData[,2:ncol(fooData)])
# Set the column headings from the first column in the original table
colnames(fooData.T) <- fooData[,1]
The result being a matrix which you're probably aware of, that's due to class issues when transposing. I don't think there will be a single line way to do this given the lack of naming abilities in the transpose step.
回答2:
I had a similar problem to this -- I had a variable of factors in a long format and I wanted each factor to be a new column heading; using "unstack" from the stats library did it in one step. If the column you want as a header isn't a factor, "cast" from the reshape library might work.
来源：https://stackoverflow.com/questions/6645524/what-is-the-best-way-to-transpose-a-data-frame-in-r-and-to-set-one-of-the-column