Re: [deal.II] weakly enforcing an identity - vector mean curvature as the surface laplacian of the identity on a codim-1 manifold

2016-08-23 Thread Wolfgang Bangerth
I implemented an exact solution for the mean curvature for ellipsoids (it's a slightly ugly expression, I just took it from here: http://math.stackexchange.com/a/540820), and I computed the L2 and Linfty errors between my computed values and that expression. The result: Convergence wrt mesh ref

Re: [deal.II] weakly enforcing an identity - vector mean curvature as the surface laplacian of the identity on a codim-1 manifold

2016-08-23 Thread thomas stephens
On Tuesday, August 23, 2016 at 12:51:53 PM UTC-4, Wolfgang Bangerth wrote: > > > Thomas, > > > I was able to solve for the vector mean curvature using the weak form of > > the identity k_bar = laplacian_X id_X, where X is a codimension 1 > > manifold without boundary. The image above is a plo

Re: [deal.II] weakly enforcing an identity - vector mean curvature as the surface laplacian of the identity on a codim-1 manifold

2016-08-23 Thread Wolfgang Bangerth
Thomas, I was able to solve for the vector mean curvature using the weak form of the identity k_bar = laplacian_X id_X, where X is a codimension 1 manifold without boundary. The image above is a plot of the square of the mean curvature on an ellipsoid with semi principle axes a=1,b=2,c=3. Gr

Re: [deal.II] weakly enforcing an identity - vector mean curvature as the surface laplacian of the identity on a codim-1 manifold

2016-08-22 Thread Wolfgang Bangerth
On 08/19/2016 01:15 PM, thomas stephens wrote: Wolfgang, I appreciate your assistance so far. I'm getting closer, but I still need some help. I would like to look at this problem as it appears in [1], Equation 27 on p. 11, as the bilinear forms are written as integrals, making things more clear

Re: [deal.II] weakly enforcing an identity - vector mean curvature as the surface laplacian of the identity on a codim-1 manifold

2016-08-19 Thread thomas stephens
Wolfgang, I appreciate your assistance so far. I'm getting closer, but I still need some help. I would like to look at this problem as it appears in [1], Equation 27 on p. 11, as the bilinear forms are written as integrals, making things more clear. Below I have set up what I think to be the

Re: [deal.II] weakly enforcing an identity - vector mean curvature as the surface laplacian of the identity on a codim-1 manifold

2016-08-18 Thread Wolfgang Bangerth
On 08/18/2016 09:39 AM, thomas stephens wrote: id_X looks like this: | template classIdentity:publicFunction { public: Identity():Function(){} virtualvoidvector_value(constPoint&p,Vector&value)const; virtualdoublevalue(constPoint&p,constunsignedintcomponent =0)const; }; Identityid_X

Re: [deal.II] weakly enforcing an identity - vector mean curvature as the surface laplacian of the identity on a codim-1 manifold

2016-08-18 Thread thomas stephens
id_X looks like this: template class Identity: public Function { public: Identity() : Function() {} virtual void vector_value(const Point &p, Vector & value) const; virtual double value(const Point &p, const unsigned int component = 0) const; }; Identity id_X(); Do I need to

Re: [deal.II] weakly enforcing an identity - vector mean curvature as the surface laplacian of the identity on a codim-1 manifold

2016-08-17 Thread Wolfgang Bangerth
On 08/17/2016 10:22 AM, thomas stephens wrote: *On to the question: *It is a fact that the vector mean curvature k_bar is equal to the surface laplacian of the identity function id_X on the manifold X, k_bar = laplace_beltrami id_X. Equation (4.4) in [1] is the weak form of this identity: (k_b