Source code for abydos.distance._baulieu_xi

# Copyright 2019-2020 by Christopher C. Little.
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Baulieu XI distance

from ._token_distance import _TokenDistance

__all__ = ['BaulieuXI']

[docs]class BaulieuXI(_TokenDistance): r"""Baulieu XI distance. For two sets X and Y and a population N, Baulieu XI distance :cite:`Baulieu:1997` is .. math:: dist_{BaulieuXI}(X, Y) = \frac{|X \setminus Y| + |Y \setminus X|} {|X \setminus Y| + |Y \setminus X| + |(N \setminus X) \setminus Y|} This is Baulieu's 29th dissimilarity coefficient. This coefficient fails Baulieu's (P4) property, that :math:`D(a+1,b,c,d) \leq D(a,b,c,d) = 0` with equality holding iff :math:`D(a,b,c,d) = 0`. In :ref:`2x2 confusion table terms <confusion_table>`, where a+b+c+d=n, this is .. math:: dist_{BaulieuXI} = \frac{b+c}{b+c+d} .. versionadded:: 0.4.0 """ def __init__( self, alphabet=None, tokenizer=None, intersection_type='crisp', **kwargs ): """Initialize BaulieuXI instance. Parameters ---------- alphabet : Counter, collection, int, or None This represents the alphabet of possible tokens. See :ref:`alphabet <alphabet>` description in :py:class:`_TokenDistance` for details. tokenizer : _Tokenizer A tokenizer instance from the :py:mod:`abydos.tokenizer` package intersection_type : str Specifies the intersection type, and set type as a result: See :ref:`intersection_type <intersection_type>` description in :py:class:`_TokenDistance` for details. **kwargs Arbitrary keyword arguments Other Parameters ---------------- qval : int The length of each q-gram. Using this parameter and tokenizer=None will cause the instance to use the QGram tokenizer with this q value. metric : _Distance A string distance measure class for use in the ``soft`` and ``fuzzy`` variants. threshold : float A threshold value, similarities above which are counted as members of the intersection for the ``fuzzy`` variant. .. versionadded:: 0.4.0 """ super(BaulieuXI, self).__init__( alphabet=alphabet, tokenizer=tokenizer, intersection_type=intersection_type, **kwargs )
[docs] def dist(self, src, tar): """Return the Baulieu XI distance of two strings. Parameters ---------- src : str Source string (or QGrams/Counter objects) for comparison tar : str Target string (or QGrams/Counter objects) for comparison Returns ------- float Baulieu XI distance Examples -------- >>> cmp = BaulieuXI() >>> cmp.dist('cat', 'hat') 0.005115089514066497 >>> cmp.dist('Niall', 'Neil') 0.008951406649616368 >>> cmp.dist('aluminum', 'Catalan') 0.01913265306122449 >>> cmp.dist('ATCG', 'TAGC') 0.012755102040816327 .. versionadded:: 0.4.0 """ if src == tar: return 0.0 self._tokenize(src, tar) bpc = self._src_only_card() + self._tar_only_card() d = self._total_complement_card() if bpc: return bpc / (bpc + d) return 0.0
if __name__ == '__main__': import doctest doctest.testmod()