SUM,COUNT,AVG
On Mon, Apr 6, 2009 at 5:31 PM, Jun Shen <jun.shen.ut at gmail.com> wrote:
This is a good example to compare different approaches. My understanding is aggregate() can apply one function to multiple columns summarize() can apply multiple functions to one column I am not sure if ddply() can actually apply multiple functions to multiple columns? This is what I would like to do. The syntax in the help is ?a little confusing to me. Appreciate more comments. Thanks
In theory, you should be able to combine colwise and each: colwise(each(min, median, max)). That should return the min, median and max for each column, but currently it doesn't return the values in quite right the form for recombination with ddply. Hadley