function [domain] = domain2faces(fem)
% determine what faces are associated with which domains
% get the up/down info
upDown=geominfo(fem.geom,'out','ud');
% domain(n) holds the faces associated with domain n-1
% domain 0 is the volume surrounding the model
domain=cell(1,max(upDown(:))+1);
% loop through the faces and add them to the appropriate domains
for i=1:length(upDown)
domain{upDown(1,i)+1}=[domain{upDown(1,i)+1},i];
domain{upDown(2,i)+1}=[domain{upDown(2,i)+1},i];
end
return;