While testing out the new UserDefinedAggregateFunction in Spark 1.5.0, I
successfully implemented a simple function to compute an average. I then
tried to test this function by applying it over a simple window and I got an
error saying that my function is not supported over window operation.
So,
The ultimate aim of my program is to be able to wrap an arbitrary Scala
function (mostly will be statistics / customized rolling window metrics) in
a UDF and evaluate them on DataFrames using the window functionality.
So my main question is how do I express that a UDF takes a Frame of rows
from a