From: Johannes Huber <johannes.huber@un...>  20110816 15:05:54

Hi, I'm using libMesh for distributed parameter identification, so my system matrix depends on a function (that might even life on another mesh). When solving the optimization problem, I need derivatives (Jacobian and hessian) not only w. r. t. PDE solution but also w. r. t. the parameter function. That works so far. When refining a mesh hanging nodes are handelt in the DofMap using constraint matricees. Since I need derivatives w. r. t. the parameter function I need access to the constraint matrix of an element. Is there a way of accessing this matrix or if there is non (DofMap::build_constraint_matrix is private) or would it be o.k. to make it public? Thanks, Hannes  ************************************************* Johannes Huber Mathematisches Institut Universität Basel Rheinsprung 21 CH4051 Basel Switzerland Phone: +41 61 267 39 93 http://www.math.unibas.ch/~huber/ ************************************************* 