Test whether a value is within some range with some fuzziness at the edges to allow for floating point noise.

fuzzy_between.py

import numpy as np

def fuzzy_between(val, minval, maxval, fuzz=2, inclusive=True):
    """
    Test whether a value is within some range with some fuzziness at the edges
    to allow for floating point noise.

    The fuzziness is implemented by expanding the range at each end `fuzz` steps
    using the numpy.nextafter function. For example, with the inputs
    minval = 1, maxval = 2, and fuzz = 2; the range would be expanded to
    minval = 0.99999999999999978 and maxval = 2.0000000000000009 before doing
    comparisons.

    Parameters
    ----------
    val : float
        Value being tested.

    minval : float
        Lower bound of range. Must be lower than `maxval`.

    maxval : float
        Upper bound of range. Must be higher than `minval`.

    fuzz : int, optional
        Number of times to expand bounds using numpy.nextafter.

    inclusive : bool, optional
        Set whether endpoints are within the range.

    Returns
    -------
    is_between : bool
        True if `val` is between `minval` and `maxval`, False otherwise.

    """
    # expand bounds
    for _ in xrange(fuzz):
        minval = np.nextafter(minval, minval - 1e6)
        maxval = np.nextafter(maxval, maxval + 1e6)

    if inclusive:
        return minval <= val <= maxval

    else:
        return minval < val < maxval