% Solve Delta u =0 over the circular sector with
% Dirichlet BC u = cos(2/3 atan(y,x)) along the arc
% and u=0 along the straight lines theta = -3pi/4, 3pi/4.
% The following commands solve the BVP by adaptive mesh refinement.
[u,p,e,t]= adaptmesh('cirsg','cirsb',1,0,0,'maxt',500, ...
                    'tripick', 'pdeadworst', 'ngen', inf);
x = p(1,:);  y= p(2,:);
% Compute the exact solution at the vertices
exact = ((x.^2+y.^2).^(1/3).*cos(2/3*atan2(y,x)))';
maxerror = max(abs(u-exact))
% Compute the number of triangles in the mesh
ntri = size(t,2)
% Plot the mesh
pdemesh(p,e,t)