On 11/19/18 11:59 PM, FU wrote: > How to get the derivative of a vector? > > > Jacobian matrix of vectors > T^4 is a vector.
That's a misunderstanding. I suspect that you have a term of the form T(x)^4 in your PDE, but if you multiply this by test function phi_i and integrate over the domain, you get a vector F_i = \int_\Omega \phi_i(x) T(x)^4 dx which is not the element-by-element fourth power of the nodal vector T that corresponds to T(x). You will want to look at how step-15 solves nonlinear problems to see how to approach such problems. Best W. -- ------------------------------------------------------------------------ Wolfgang Bangerth email: bange...@colostate.edu www: http://www.math.colostate.edu/~bangerth/ -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to dealii+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.