On 28 April 2012 11:38, Felipe Almeida Lessa
Hello!
I'm sorry if this is a dumb question, I was just reading the API docs, but: what happens if one by one I add all edges of a non-planar graph using addEdge? Are there any sanity checks that would tell me "sorry, but your graph isn't planar", or would it just give me wrong answers?
Wrong answers. I'm assuming you have *some* intelligence :p The original plans were to have Maybe variants that would perform such sanity checks, but as I was going for performance (as my supervisor is of the opinion that if it isn't C it isn't worth considering for pure performance reasons) the default versions didn't include them, and it slipped my mind until you just reminded me :) I can add them in if anyone wants them: what it entails is to add the edge and then perform planarity testing [3]; this can get expensive if the graph is large (I did once work out an approach that involved just checking the new face[s], but I don't recall what it was or whether it was correct). [3]: http://en.wikipedia.org/wiki/Planarity_testing (My rationale for this library was to implement a graph-generating algorithm; I knew what the ordering was, so I didn't need any "will adding this keep it planar" checks.) -- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com http://IvanMiljenovic.wordpress.com