Dear Getfem++ users,
I would like to use Nedelec finite element to calculate the mode of 3d
electromagnetic cavity.
I'm using the matlab interface.
The importation of the mesh, definition of element and integration method is
fine:
m = gf_mesh('import', 'gmsh', 'cylinder.msh');
mf = gf_mesh_fem(m,3);
gf_mesh_fem_set(mf,'fem',gf_fem('FEM_NEDELEC(3)'));
mim=gfMeshIm(m,gf_integ('IM_TETRAHEDRON(8)'));
To assemble the term \int E.E'dx I'm using:
Ma=gf_asm('volumic','M(#1,#1)+=comp(vBase(#1).vBase(#1))(:,k,:,k)', mim,mf);
I got the same result with "gf_asm('mass matrix', mim, mf);" ( as excepted)
For the "stiffness" matrix \int curlE curlE' dx i'm using:
K=gf_asm('volumic','M(#1,#1)+=comp(vGrad(#1).vGrad(#1))(:,2,3,:,2,3)+comp(vGrad(#1).vGrad(#1))(:,3,2,:,3,2)-comp(vGrad(#1).vGrad(#1))(:,2,3,:,3,2)-comp(vGrad(#1).vGrad(#1))(:,3,2,:,2,3)+comp(vGrad(#1).vGrad(#1))(:,3,1,:,3,1)+comp(vGrad(#1).vGrad(#1))(:,1,3,:,1,3)-comp(vGrad(#1).vGrad(#1))(:,3,1,:,1,3)-comp(vGrad(#1).vGrad(#1))(:,1,3,:,3,1)+comp(vGrad(#1).vGrad(#1))(:,1,2,:,1,2)+comp(vGrad(#1).vGrad(#1))(:,2,1,:,2,1)-comp(vGrad(#1).vGrad(#1))(:,1,2,:,2,1)-comp(vGrad(#1).vGrad(#1))(:,2,1,:,1,2)',
mim,mf);
My problem is that the obtained matrix K is not positive definite (and it
should be...).
Does anyone have a suggestion why the K matrix is not positive definite?
Thank you in advance for the answer.
Best Regards
Louis Kovalevsky
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