function B = drcavity% drcavity.m A nonlinear algebraic equation model object constructor, derived%            from the naemodel class. Called as%%           A = drcavity%% INPUT PARAMETERS%% wafer parametersnx = 12;ny = 12;X = quadgrid('slab',nx,'x');Y = quadgrid('slab',ny,'y');Dx  = linearoperator(X,'d', 'x');DDx = linearoperator(X,'dd','x');Dy  = linearoperator(Y,'d', 'y');DDy = linearoperator(Y,'dd','y');S = X*Y;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% set up an instance of the gasflow object% Solution initial guessvx = scalarfield(S,rand(nx,ny));vy = scalarfield(S,rand(nx,ny));p  = scalarfield(S,rand(nx,ny));vybc = scalarfield(S,1);vybc = setbval(vybc,scalarfield(S,0),'y','min');vybc = setbval(vybc,scalarfield(S,0),'y','max');vybc = bpsf(vybc,2,'y');var   = assocarray({'vx' vx 'vy' vy 'p' p});param = assocarray({ 'vybc' vybc 'DDx' DDx 'DDy' DDy ...                     'Dx' Dx 'Dy' Dy 'S' S});A = naemodel('drcavity',var,param);B = struct([]);B = class(B,'drcavity',A);