# Copyright 2019-2020 by Christopher C. Little.
# This file is part of Abydos.
#
# Abydos is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Abydos is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Abydos. If not, see <http://www.gnu.org/licenses/>.
"""abydos.distance._rouge_su.
Rouge-SU similarity
"""
from . import RougeS
__all__ = ['RougeSU']
[docs]class RougeSU(RougeS):
r"""Rouge-SU similarity.
Rouge-SU similarity :cite:`Lin:2004`, operating on character-level
skipgrams
.. versionadded:: 0.4.0
"""
def __init__(self, qval=2, **kwargs):
"""Initialize RougeSU instance.
Parameters
----------
**kwargs
Arbitrary keyword arguments
.. versionadded:: 0.4.0
"""
super(RougeSU, self).__init__(qval=qval, **kwargs)
[docs] def sim(self, src, tar, beta=8):
"""Return the Rouge-SU similarity of two strings.
Parameters
----------
src : str
Source string for comparison
tar : str
Target string for comparison
beta : int or float
A weighting factor to prejudice similarity towards src
Returns
-------
float
Rouge-SU similarity
Examples
--------
>>> cmp = RougeSU()
>>> cmp.sim('cat', 'hat')
0.5
>>> cmp.sim('Niall', 'Neil')
0.4020618556701031
>>> cmp.sim('aluminum', 'Catalan')
0.1672384219554031
>>> cmp.sim('ATCG', 'TAGC')
0.8
.. versionadded:: 0.4.0
"""
return super(RougeSU, self).sim(
'$' * (self._qval - 1) + src, '$' * (self._qval - 1) + tar, beta
)
if __name__ == '__main__':
import doctest
doctest.testmod()