vertex2edge.m

解决麦克斯韦的matlab源文件

function ev = vertex2edge(mesh,nv)
% Edge element interpolant of p.w. linear continuous vectorfield
% on unstructured mesh
%
% mesh -> data structure for 2D unstructured grid
% nv -> column vector of legth 2*mesh.Nv, containing x/y-components of 
%       vectorfield at vertices
%
% Result ev -> Column vector of length mesh.Ne
%

if (size(nv,1) ~= 2*mesh.Nv), error('Size mismatch for argument vector'); end
if (size(nv,2) ~= 1), error('nv must be a column vector'); end

ev = zeros(mesh.Ne,1);

for i=1:mesh.Ne
  vidx = mesh.ep(i,:);
  edgeo = mesh.vt(vidx,:)';
  ed = edgeo(:,2)-edgeo(:,1);
  mfield = 0.5*sum([nv(2*vidx-1)'; nv(2*vidx)']')';
  ev(i) = dot(ed,mfield);
end