On 2/24/13, km <[email protected]> wrote: > pairs =: [: ,/ [: (2 ,/\ ])"1 (, |:) NB. Constructs left-right and > up-down arcs > pairs i. 3 3 NB. left-right and up-down arcs
This is a nice trick to create the list of edges. However, it doesn't work for a non-square matrix. For example, (pairs i. 3 4) will contain the edge (9 0) which shouldn't really be there. > CM=: #. e.~ [: i. [ , [ NB. Borrowed from 20. Directed Graphs in > Dictionary I find this method of converting the list to the adjacency matrix strange. I would instead use the amend verb, like this: CM =: (1:`(<"1@[)`]} 0$~,~)~ Ambrus ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
