John's solution below may be modified. Let the eight corners be >:#:i.8 1 1 1 1 1 2 1 2 1 1 2 2 2 1 1 2 1 2 2 2 1 2 2 2
Use the zero as a wildcard character. So the twelve edges are 0 1 1 0 1 2 0 2 1 0 2 2 1 0 1 1 0 2 1 1 0 1 2 0 2 0 1 2 0 2 2 1 0 2 2 0 and the six faces are 0 0 1 0 0 2 0 1 0 0 2 0 1 0 0 2 0 0 and the cube itself is 0 0 0 The twentyseven elements of the cube are coded by 3 3 3 #: i.27 0 0 0 0 0 1 0 0 2 0 1 0 0 1 1 0 1 2 0 2 0 0 2 1 0 2 2 1 0 0 1 0 1 1 0 2 1 1 0 1 1 1 1 1 2 1 2 0 1 2 1 1 2 2 2 0 0 2 0 1 2 0 2 2 1 0 2 1 1 2 1 2 2 2 0 2 2 1 2 2 2 --- Den fre 2/4/10 skrev John Randall <[email protected]>: Fra: John Randall <[email protected]> Emne: Re: [Jprogramming] cubes Til: "Programming forum" <[email protected]> Dato: fredag 2. april 2010 16.59 Raul Miller wrote: > I am looking for elegant ways of describing cubes in J. Here is an alternative system for cube coordinates. Label the points #: i. 8 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1 Now a face is given by a set of points with 1 coordinate fixed, e.g. 0 0 0 0 0 1 1 0 0 1 0 1 and an edge is given by a set of points with 2 coordinates fixed, e.g. 1 0 0 1 0 1 This generalizes to higher dimensional cubes. Best wishes, John ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm __________________________________________________ Bruger du Yahoo!? Er du træt af spam? Yahoo!Mail har den bedste spambeskyttelse, der findes http://dk.mail.yahoo.com ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
