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Posets :: rankFunction

rankFunction -- computes the rank function of a ranked poset

Synopsis

Description

The poset P is ranked if there exists an integer function r on the vertex set of P such that for each a and b in the poset if b covers a then r(b) - r(a) = 1.

This method returns one such ranking function.
i1 : rankFunction chain 5

o1 = {0, 1, 2, 3, 4}

o1 : List
i2 : rankFunction booleanLattice 3

o2 = {0, 1, 1, 2, 1, 2, 2, 3}

o2 : List
This method was ported from John Stembridge’s Maple package available at http://www.math.lsa.umich.edu/~jrs/maple.html#posets.

See also

Ways to use rankFunction :