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?

Question

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

Solution 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.

Solution 2

You can do it even in one line:

fooData.T <- setNames(data.frame(t(fooData[,-1])), fooData[,1])

There are already great answers. However, this answer might be useful for those who prefer brevity in code.

Solution 3

Here are my two cents using dplyr for a data.frame that has grouping columns and an id column.

id_transpose <- function(df, id){
  df %>% 
    ungroup() %>% 
    select(where(is.numeric)) %>% 
    t() %>% 
    as_tibble() %>% 
    setNames(., df %>% pull({{id}}))
}

Comments

[Waldir Leoncio]

possible duplicate of R-Transposing a data frame

[themartinmcfly]

Good point, this should make it faster as far as I can tell, as it is having to transpose less data. Plus looks neater. The matrix issue is one of the issues I ran into also and had to use a class(fooData.T) <- "numeric", which won't work for any other data types.

[themartinmcfly]

I am making this the answer as there aren't any other alternatives, which is strange for programming as there is usually a multitude of ways to solve something.

[domi]

There is a problem with the second instruction, it should be colnames(fooData.T) <- t(fooData[,1])