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Markov bases for two-way subtable sum problems

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 نشر من قبل Hisayuki Hara
 تاريخ النشر 2007
  مجال البحث
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It has been well-known that for two-way contingency tables with fixed row sums and column sums the set of square-free moves of degree two forms a Markov basis. However when we impose an additional constraint that the sum of a subtable is also fixed, then these moves do not necessarily form a Markov basis. Thus, in this paper, we show a necessary and sufficient condition on a subtable so that the set of square-free moves of degree two forms a Markov basis.



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