Calculate Range
On 11/17/2013 08:49 AM, SCRIPTHAM wrote:
Hi My R version is the current version as at 15 Nov 2013. I have tried to calculate range using tapply() with FUN=range. tapply() returns two fields, the ID field and a field of two text items one is the maximum and the other is the minimum. I take as the difference max - min, does R use a different term for range in tapply? I have also tried aggregate() with Fun=range, with Fun=min and FUN=max and they also gave problems. What is the best route to calculate ranges for groups within a data frame.
Hi Scriptham, It looks like you want to get the difference between the maximum and minimum values rather than the actual values. Define a function: range_span<-function(x) return(diff(range(x))) and use that as the FUN argument. Jim