From: Roy Stogner <roystgnr@ic...>  20060402 00:08:46

On the QUAD elements, we handled flipped edges by taking the negative of the odd shape functions on those edges, which works fine. On the HEX27, it looks like we're handling flipped edges by mapping xi to xi, eta to eta, or zeta to zeta, depending on the edge. Obviously this mapping gives you the negative of odd shape functions... but it doesn't give you the negative of their derivatives! Am I missing something, or is this incorrect? We now (or whenever SourceForge gets their CVS server working again, anyway) have hierarchics implemented for arbitrary n on EDGE2/3 and QUAD8/9 elements, by the way. They only seem to work well up to n=11 or so, though; I'm not sure whether it's the floating point function evaluations or the matrix conditioning that blows up there, but something goes haywire.  Roy 