Creating a dataframe from a vector of character strings
On 15/04/11 09:04, Cliff Clive wrote:
I have a vector of character strings that I would like to split in two, and
place in columns of a dataframe.
So for example, I start with this:
beatles<- c("John Lennon", "Paul McCartney", "George Harrison", "Ringo
Starr")
and I want to end up with a data frame that looks like this:
Beatles = data.frame(firstName=c("John", "Paul", "George", "Ringo"),
lastName=c("Lennon", "McCartney", "Harrison",
"Starr"))
Beatles
firstName lastName 1 John Lennon 2 Paul McCartney 3 George Harrison 4 Ringo Starr I tried string-splitting the first vector on the spaces between first and last names, and it returned a list:
strsplit(beatles, " ")
[[1]] [1] "John" "Lennon" [[2]] [1] "Paul" "McCartney" [[3]] [1] "George" "Harrison" [[4]] [1] "Ringo" "Starr" Is there a fast way to convert this list into a data frame? Right now all I can think of is using a for loop, which I would like to avoid, since the real application I am working on involves a much larger dataset
Whenever you think of using a for loop, stop and think about using
some flavour of apply() instead:
melvin <- strsplit(beatles," ")
clyde <- data.frame(firstName=sapply(melvin,function(x){x[1]}),
lastName=sapply(melvin,function(x){x[2]}))
cheers,
Rolf Turner