Index of /StackMax547/maxima-5.47.0/share/combinatorics/

Robert Dodier, February 2006: ----------------------------- There were two files here which implemented two versions of a permutation function, both of which are superseded by the permutation function in maxima/src/nset.lisp. Jaime Villate, November 2017: ----------------------------- I have added a package that implements some of the permutations functions of Macsyma (with different names) and will implement many more functions. Since Maxima's nset package already includes functions permutations and random_permutation which return permuted arrangements of a set or list, I have used the name "perm" for permutations written as a list of the first n positive integers without repetitions. Thus, perms(int) will give the list of permutations of degree n, in contrast to permutations(set) which gives that list of permutations applied to the elements of a set. Some differences with Macsyma: permutation_decomp has been named here perm_cycles and perm_decomp is used for decomposition into the generators of the permutation group (adjacent transpositions). perm_cycles returns only cycles and no fixed points; i.e, [[1,4,5],[3,6]] instead of [[1,4,5],[2],[3,6]]. perm_undecomp does not require a complete set of cycles and fixed points, such as [[1,4,5],[2],[3,6],[7]]; it accepts just [[1,4,5],[3,6]], but it needs an extra parameter, namely, the degree of the group. For example: perm_undecomp([[1,4,5],[3,6]],7) perms_lex returns the list of permutations of degree n in lexicographic order, but unlike Macsyma's permutations_lex, the argument should be just an integer (n) and not a permutation. perms(n) gives tht complete list of permutations using a minimum-change ordering, in which is permutation differs from the previous one by just one adjacent transposition.