rr.approx 0.1.1

A simple module for approximate floating point arithmetic.

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.

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.

from rr.approx import Approx

print Approx.Context()  # display current context
Approx.Context(1e-4, 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()

Installation

pip install rr.approx