public class GetPmfFromDoublesSketch
extends org.apache.pig.EvalFunc<org.apache.pig.data.Tuple>
This UDF is to get an approximation to the Probability Mass Function (PMF) of the input stream
given a sketch and a set of split points - an array of m unique, monotonically increasing
double values that divide the real number line into m+1 consecutive disjoint intervals.
The function returns an array of m+1 doubles each of which is an approximation to the fraction
of the input stream values that fell into one of those intervals. Intervals are inclusive of
the left split point and exclusive of the right split point.