Polar

Polar implements a novel static analysis technique to derive higher moments for program variables for a large class of probabilistic loops with potentially uncountable state spaces.

Installation

To install Polar, you can do the following steps.

1. Make sure you have python (version ≥ 3.8) and pip installed on your system. Otherwise install it in your preferred way.

2. Clone the repository:

   git clone git@github.com:probing-lab/polar.git
   cd polar
   

3. Create a virtual environment in the .venv directory:

   pip install --user virtualenv
   python -m venv .venv
   

4. Activate the virtual environment:

   source .venv/bin/activate
   

5. Install the required dependencies:

   pip install -r requirements.txt
   

Usage

python polar.py benchmarks/polar_paper/illustrating.prob --goals "E(z)"

The parameter goals takes any expected value of monomials of program variables, for instance "E(x**2)", "E(t*x**2)", etc. To compute the variance you can pass "c2(x)". In general, to compute the kth central moment (where k is a natural number), pass "ck(x)" to the goals parameter.

For a list of all parameters supported by Polar run:

python polar.py --help

Run Tests

You can run the automatic test suite with:

python -m unittest

To run flake8, a tool for style guide enforcement, first install it with:

pip install flake8

After installation flake8 can be executed by running:

flake8 .