Represents an
empirical probability distribution -- a probability distribution derived
from observed data without making any assumptions about the functional form
of the population distribution that the data come from.
Implementations of this interface maintain data structures, called
distribution digests, that describe empirical distributions and
support the following operations:
loading the distribution from a file of observed data values
dividing the input data into "bin ranges" and reporting bin frequency
counts (data for histogram)
reporting univariate statistics describing the full set of data values
as well as the observations within each bin
generating random values from the distribution
Applications can use EmpiricalDistribution implementations to
build grouped frequnecy histograms representing the input data or to
generate random values "like" those in the input file -- i.e., the values
generated will follow the distribution of the values in the file.