This partially extends Statistics::Descriptive to handle weighted
variates.

Although some functionality of Statistics::Descriptive has been lost
other functionality has been added, in particular a cdf function and
other related functions. (see man page for details).

The implementation uses Tree::Treap which, since it is not on CPAN, is
provided and automatically installed with this package. This is an
implementation of a randomized self-balancing binary search tree called a
treap.

To install this package:

perl Makefile.pl
make
make test
(sudo) make install
man Statistics::Descriptive::Weighted

List of methods by class:

Statistics::Descriptive::Weighted::Sparse
----------------------------------
add_data
count
mean
weight
sum
variance
min
max
standard_deviation
sample_range

Statistics::Descriptive::Weighted::Full
----------------------------------
All methods above and:

get_data
percentile
median
mode
maxweight
cdf
survival
rtp
quantile
print