/h^TSrSSKrSSjrSrSrS SjrS Sjrg!\a Nf=f) a  Text Segmentation Metrics 1. Windowdiff Pevzner, L., and Hearst, M., A Critique and Improvement of an Evaluation Metric for Text Segmentation, Computational Linguistics 28, 19-36 2. Generalized Hamming Distance Bookstein A., Kulyukin V.A., Raita T. Generalized Hamming Distance Information Retrieval 5, 2002, pp 353-375 Baseline implementation in C++ http://digital.cs.usu.edu/~vkulyukin/vkweb/software/ghd/ghd.html Study describing benefits of Generalized Hamming Distance Versus WindowDiff for evaluating text segmentation tasks Begsten, Y. Quel indice pour mesurer l'efficacite en segmentation de textes ? TALN 2009 3. Pk text segmentation metric Beeferman D., Berger A., Lafferty J. (1999) Statistical Models for Text Segmentation Machine Learning, 34, 177-210 Nc[U5[U5:wa [S5eU[U5:a [S5eSn[[U5U- S-5HSn[XXb-R U5XXb-R U5- 5nU(aXW- nMDU[ SU5- nMU U[U5U- S-- $)a Compute the windowdiff score for a pair of segmentations. A segmentation is any sequence over a vocabulary of two items (e.g. "0", "1"), where the specified boundary value is used to mark the edge of a segmentation. >>> s1 = "000100000010" >>> s2 = "000010000100" >>> s3 = "100000010000" >>> '%.2f' % windowdiff(s1, s1, 3) '0.00' >>> '%.2f' % windowdiff(s1, s2, 3) '0.30' >>> '%.2f' % windowdiff(s2, s3, 3) '0.80' :param seg1: a segmentation :type seg1: str or list :param seg2: a segmentation :type seg2: str or list :param k: window width :type k: int :param boundary: boundary value :type boundary: str or int or bool :param weighted: use the weighted variant of windowdiff :type weighted: boolean :rtype: float z!Segmentations have unequal lengthzCWindow width k should be smaller or equal than segmentation lengthsr?)len ValueErrorrangeabscountmin)seg1seg2kboundaryweightedwdindiffs Q/var/www/auris/envauris/lib/python3.13/site-packages/nltk/metrics/segmentation.py windowdiffr1s< 4yCI<==3t9} Q   B 3t9q=1$ %DQUO))(3dquo6K6KH6UUV  KB #a- B & TQ$ %%c[R"X45nU[R"U5-USSS24'U[R"U5-USS2S4'U$)Nr)npemptyarange)nrowsncolsins_costdel_costmats r _init_matr bsM ((E> "C299U++C1I299U++C1I Jrc[U5Hnupg[U5HZupU[Xy- 5-XU4-n Xy:XaXU4n OXy:a X@XhS-4-n O X0US-U4-n [X5XS-US-4'M\ Mp g)Nr) enumerater r ) rrowvcolvrrshift_cost_coeffrrowijcolj shift_costtcosts r_ghd_auxr+isT? GA)C ,<>> # Same examples as Kulyukin C++ implementation >>> ghd('1100100000', '1100010000', 1.0, 1.0, 0.5) 0.5 >>> ghd('1100100000', '1100000001', 1.0, 1.0, 0.5) 2.0 >>> ghd('011', '110', 1.0, 1.0, 0.5) 1.0 >>> ghd('1', '0', 1.0, 1.0, 0.5) 1.0 >>> ghd('111', '000', 1.0, 1.0, 0.5) 3.0 >>> ghd('000', '111', 1.0, 2.0, 0.5) 6.0 :param ref: the reference segmentation :type ref: str or list :param hyp: the hypothetical segmentation :type hyp: str or list :param ins_cost: insertion cost :type ins_cost: float :param del_cost: deletion cost :type del_cost: float :param shift_cost_coeff: constant used to compute the cost of a shift. ``shift cost = shift_cost_coeff * |i - j|`` where ``i`` and ``j`` are the positions indicating the shift :type shift_cost_coeff: float :param boundary: boundary value :type boundary: str or int or bool :rtype: float rgr)r-)r"rr r+float) refhyprrr%rrvalref_idxhyp_idx nref_bound nhyp_boundrs rghdr6ys\"+3CXa3?qGC!*3CXa3?qGCWJWJQ:? aJ!O$$ qZ!^$$ JNJNH GC S7hI V DCs B>B> CCcRUc2[[[U5URU5S-- 55nSn[ [U5U- S-5H?nXXR-RU5S:nXXR-RU5S:nXg:wdM:US- nMA U[U5U- S-- $)a Compute the Pk metric for a pair of segmentations A segmentation is any sequence over a vocabulary of two items (e.g. "0", "1"), where the specified boundary value is used to mark the edge of a segmentation. >>> '%.2f' % pk('0100'*100, '1'*400, 2) '0.50' >>> '%.2f' % pk('0100'*100, '0'*400, 2) '0.50' >>> '%.2f' % pk('0100'*100, '0100'*100, 2) '0.00' :param ref: the reference segmentation :type ref: str or list :param hyp: the segmentation to evaluate :type hyp: str or list :param k: window size, if None, set to half of the average reference segment length :type boundary: str or int or bool :param boundary: boundary value :type boundary: str or int or bool :rtype: float @rrr)introundrr r)r/r0rrerrrrhs rpkr>s2 y c#h#))H"5";<= > C 3s8arrrDsC@  +&b 7 =F"&_  s ''