Is anyone actively using the gradient export functionality of PyFR? That is to say export -g …? In my experience it tends to produce worse results than current versions of ParaView’s gradient of unstructured data set filter, and hence seems somewhat redundant.
The gradients come from simply differentiating the basis polynomials inside of each element without consideration for neighbouring elements. By comparison the ParaView filter, run after a clean to grid, can do a much better reconstruction by considering all neighbours (including those which share common vertices — something which PyFR does not even have a concept of since we’re a discontinuous code).