semvec/pypi-packages huggingface dataset:
rr.approx 0.1.2
A simple module for approximate floating point arithmetic.
License: MIT

=========
rr.approx
=========

Approximate floating point arithmetic library. This simple module can be used to compare numbers using a relative and absolute tolerance, to mitigate floating point rounding errors.

.. code-block:: python

    from rr.approx import Approx

    x = Approx(0.1) * 3
    print x == 0.3  # True

The ``Approx`` class is very simple to use as a replacement for "regular" floats -- you can use ``Approx`` objects instead of floats in most (if not all) contexts: arithmetic and comparisons.

The ``ApproxContext`` class, also accessible as ``Approx.Context``, provides a context manager to temporarily modify the module's tolerance parameters.

.. code-block:: python

    print Approx.Context()  # display current context
    Approx.Context(rtol=1e-4, atol=1e-2).apply()  # permanently modify tolerances
    print Approx.Context()
    with Approx.Context(rtol=1e-5, atol=1e-3):  # temporary modification
        print Approx.Context()
    print Approx.Context()

Disclaimer
----------

Please note that this module **does not solve** any problems with floating point numbers. What it does is provide a little (or big, depending on how you configure your tolerance parameters) buffer to compensate for rounding errors, but as these errors accumulate you can always get unexpected results.

**Float rounding is inherently innaccurate** in all computers and programming languages due to representing a possibly recurring decimal in a finite number of digits. If you really care about exact results and don't mind paying a performance penalty, you should check out the `decimal <https://docs.python.org/2/library/decimal.html>`_ module from the standard library or some other alternative.

Installation
------------

>From PyPI ("stable" release):

.. code-block:: bash

    pip install rr.approx

Or from the Git repo:

.. code-block:: bash

    git clone https://github.com/2xR/rr.approx.git
    pip install ./rr.approx


Contributing
------------

Contributions are welcome through github pull requests (tests would sure be nice to have... :P).

And if you're using the library and would like to say *"thanks!"* and/or keep me working on it, why not `buy me a beer <https://www.paypal.com/cgi-bin/webscr?cmd=_donations&business=2UMJC8HSU8RFJ&lc=PT&item_name=DoubleR&item_number=github%2f2xR%2fpaypal&currency_code=EUR&bn=PP%2dDonationsBF%3abtn_donate_LG%2egif%3aNonHosted>`_?

Happy approximate comparisons!