function err=model_laplace_test n1=10; n2=5; h1=0.5;h2=2; a=-1; b=5;c=3; jmf=model_laplace(n1,n2,h1,h2); K=assemble(jmf.Kloc,jmf.ien,jmf.id); disp('test of model_laplace with linear solution, result should be zero') x=jmf.xyz(:,1); y=jmf.xyz(:,2); u=a*x+b*y+c; f=K*u; load=zeros(n1+1,n2+1); load(2:n1,1)=-a*h2; load(2:n1,1+n2)=a*h2; load(1,2:n2)=-b*h1; load(1+n1,2:n2)=b*h1; load(1,1)=0.5*(-a*h2-b*h1); load(1+n1,1)=0.5*(-a*h2+b*h1); load(1+n1,1+n2)=0.5*(a*h2+b*h1); load(1,1+n2)=0.5*(a*h2-b*h1); err=norm(f-load(:),1);