We need to balance the proportion of positive ratings with the uncertainty of a small number of observations. Fortunately, the math for this was worked out in 1927 by Edwin B. Wilson. What we want to ask is: Given the ratings I have, there is a 95% chance that the "real" fraction of positive ratings is at least what?

CVXOPT is a free software package for convex optimization based on the Python programming language. It can be used with the interactive Python interpreter, on the command line by executing Python scripts, or integrated in other software via Python extension modules. Its main purpose is to make the development of software for convex optimization applications straightforward by building on Python’s extensive standard library and on the strengths of Python as a high-level programming language.

PDL ("Perl Data Language") gives standard Perl the ability to compactly store and speedily manipulate the large N-dimensional data arrays which are the bread and butter of scientific computing.

PDL turns perl in to a free, array-oriented, numerical language similar to (but, we believe, better than) such commerical packages as IDL and MatLab. One can write simple perl expressions to manipulate entire numerical arrays all at once. For example, using PDL the perl variable $a can hold a 1024x1024 floating point image, it only takes 4MB of memory to store it and expressions like $a=sqrt($a)+2 manipulate the whole image in a few milliseconds.

A simple interactive shell (perldl) is provided for use from the command line and a module (PDL) for use in perl scripts.

The PDL distribution for Perl is free Software and provides extensive numerical and semi-numerical functionality with support for two- and three-dimensional visualisation as well as a variety of I/O formats.

Description of TeX packages and commands for math mode.