data.frame from lists in list, weird column names

Question

I'm trying to make a data.frame from a "list in list"

l <- list(c("sam1", "GSM6683", "GSM6684", "GSM6687", "GSM6688"), c("sam2", 
"GSM6681", "GSM6682", "GSM6685", "GSM6686"))
df <- data.frame(l)

1) I get a date.frame with weird column names, how can I avoid it? 2) I'd like to get the column names from the first element of the inner list in list

like so:

column names: sam1, sam2
row1 GSM6683 GSM6681
row2 GSM6684 GSM6682
row3 GSM6687 GSM6685
row4 GSM6688 GSM6686

Answer 1

If you're starting with the data structure in your example, do this:

df <- data.frame(lapply(l, function(x) x[-1]))
names(df) <- lapply(l, function(x) x[1])

If you have a choice on how to construct the data structure, do what R_Newbie says in his answer.

Answer 2

You were almost there, since you want sam1 and sam2 to be column names you don't need to make them part of you list and specify they are column names.

>l <- list(c("GSM6683", "GSM6684", "GSM6687", "GSM6688"), c( 
    "GSM6681", "GSM6682", "GSM6685", "GSM6686"))
>df <- data.frame(l)
>colnames(df)<-c("sam1", "sam2")