unique: factor to string
On Jan 18, 2010, at 10:05 AM, Markus M?hlbacher wrote:
Hi community, I want to count the occurrence of values within a dataframe. data$names is a list of many names.
It's most likely a vector.
With namelist <- unique(data$names) I get all the existing names. But the result is a factor, not a list of strings.
as.character(data$names) # would be a character vector, i.e., a structure composed of "strings" # You could make it a list if you wanted, but it's not clear that is needed for your purposes.
I would then like to go trough all the names in a for-loop and count their occurrence.
That shows your C programming background. Try instead the loop-less method: table(data$names) BTW using "names" for an object's name is not a good programing practice in R because there is a useful function by the same name. ..... and then there is always the "dog" fortune. -- David.
David Winsemius, MD Heritage Laboratories West Hartford, CT