user297400 questions

• How to compute weighted means of a vector within factor levels?
• What is the most efficient way to return ranks of a vector within levels of a factor, as a vector having the same order/length as the original vector?
• How Can I vectorize this function to return an index vector?
• Async.Parallel or Array.Parallel.Map?
• How to obtain a list of directories within a directory, like list.files(), but instead "list.dirs()"

user297400 answers