I am looking for elegant ways of describing cubes in J. For example:
points=: _1+2*#:i.8 surfaces=: 1 A. I. (, 1 - |.) 8&$...@#&0 1">4 2 1 Here, points is a list of vertices and a vertex is a list of xyz coordinates, and surfaces is a list of polygons where a polygon is a list of four vertex indices. Here, I consider 'points' to be elegant, but I am looking for something more meaningful (and yet still concise) for surfaces. Here is an example of an equivalent but more meaningful expression for surfaces: surfaces=: 1 A."1 I. (#~ (1 e. [: */^:2 0: = points -"1/~...@#~ ])"1) (#~ 4=+/"1)#:i.2^#points Here, I start by generating every combination of the available points, choosing those combinations which have four points, then choosing those combinations which are coplanar and then rearranging them. This is somewhat meaningful (though that 1 A. bothers me), but it is not concise. Does anyone have any good ideas for a meaningful sentence to define 'surfaces'? Thanks, -- Raul ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
