gpf

 pde for GP after Lashkin08

0001 function [c,a,f,b]=gpf(p,u,lam) 
0002 % pde for GP after Lashkin08
0003 mu=p.mu; c=[1;0;0;1;1;0;0;1]; 
0004 x=p.points(1,:)'; y=p.points(2,:)'; r=x.^2+y.^2; 
0005 pot=p.pa*pdeintrp(p.points,p.tria,r);
0006 ui=pdeintrp(p.points,p.tria,u); u=ui(1,:); v=ui(2,:); ua=u.^2+v.^2; 
0007 xi=pdeintrp(p.points,p.tria,x);yi=pdeintrp(p.points,p.tria,y);
0008 f1=ua.*u; f2=ua.*v; f=[f1;f2]; a=[-mu+pot;-mu+pot]; % a is diagonal
0009 b=zeros(p.neq*p.neq*2,p.nt); 
0010 b(3,:)=yi;b(4,:)=-xi;b(5,:)=-yi;b(6,:)=xi; b=lam*b;