From: Vetter Roman <vetterro@st...>  20101214 10:35:36

Hello there. I'm using a 1D mesh with (cubic) Hermite shape functions to implement a beam. Each element comes with four dof_indices per variable, namely the nodal value and its derivative for each of the two nodes. In beam theory, when using Hermite shape fcts, the derivative dofs are treated differently than the normal ones in that their stiffness matrix entries are different. Thus, when building the stiffness matrix, I need to now which entries of the dof_indices vector corresponds to which type of dof. To be a bit more specific: Currently, I'm iterating over all active_local_elements. For each of these, I determine the dof_indices vector, which, for 3 variables, has a size of 12. For each entry in dof_indices, I would like to know three things: a) the variable number it belongs to, b) the node it belongs to, c) "normal" dof or derivative dof, so I can build the 12x12 element stiffness matrix correspondingly. I'm looking for the "intended" way to do it, i.e. such that my code would still be correct after doing AMR or even using different shape functions, both of which I'm planning to do. I reckon that the two components per variable (n_comp(s,vn) == 2) precisely represent the value and the derivative, for each node, right? (source: http://www.mailarchive.com/libmeshdevel@.../msg00844.html) Is the ordering always guaranteed to be this way? Thanks for helping me with this. Roman 