Re: [firedrake] Interpolating with FacetNormal giving AssertionError

Dear Andrew,

On 9 Nov 2020, at 04:17, Andrew Hicks <ahick17@lsu.edu> wrote:

Dear Firedrakers,

I’ve encountered an issue in my code where it won’t allow me to interpolate anything containing a reference to a defined FacetNormal onto a Function. Here is a snippet of code where I purposefully tried to put the bare minimum required to get the error:

H1 = VectorFunctionSpace(mesh,’CG’,1,5) x0,x1,x2 = SpatialCoordinate(mesh)

nu = FacetNormal(mesh)

h = interpolate(as_vector([nu[0],0,0,0,0]),H1)

The issue here is that interpolation works cell-wise, whereas a FacetNormal is only defined on the faces of the mesh. Thanks, Lawrence