Hi,
I am new to fenics.
I am solving a pde and managed to get a solution, say ‘u’. I am interested in evaluating the gradient of the solution, ‘grad(u)’ . The plot function manages to plot it, but I want to evaluate grad(u) at specific points.
I can evaluate u simply by u(Point(0,0), but how do I evaluate grad(u)?
Something like
p=point(x1,y1)
gu=grad(u)
gu§
Thanks!
P.S. Where can I learn more about these kind of things? I find it hard jumping from the initial fenic tutorial to find how all of these works