Permutations

Content

Functions for permutations.

Load this file with "load perm".

pn := 10;

function pid (n)

  Identity permutation of n elements.

function pmult (p,q)

  Multiply two permutations.

function operator pm (p,q)

  Multiply two permutations.
  
  >pprint ptranspose(2,3,10) pm ptranspose(3,4,10)
  (2 3 4)

function ptranspose (i,j,n=none)

  Transposition of i and j in n elements.

function prefix pprint (p)

  Print a permutation as product of cycles.

function pcycle (q,n=none)

  Transform a cycle q into a permutation of n elements.

function pinverse (p)

  Inverse of the permutation p.

function pmultcycles

  Multiply all cycles in the argument list (right to left).

function forAllPerm (f,n)

  Run f(p) for all permutations p of n elements.

function forAllChoices (f,n,m)

  Run f(p) for all choices p of m elements out of 1:n

function forAllTrips (f,n)

  Run f(p) for all trips p of n elements.

function forAllOrderedChoices (f,n,m)

  Run f(p) for all ordered tuples of m elements in 1 to n.