Rigid element example

The SDT documentation is kind of sketchy on the use of rigid constraints. Here is the simple example of a plate with a rigid edge

 femesh('reset');
femesh(';testquad4;divide 10 10;addsel');
model=femesh('model');

% Define a rigid edge
femesh('selelt seledge & innode{x==0}') 
femesh('setgroupa1 name rigid')
FEel0(femesh('findel0 group1'),3)=123456;
FEel0(femesh('findel0 group1'),4)=0;
model=fe_case(model,'addtocase1','rigid','Rigid edge',FEel0);

% Compute and display modes
def=fe_eig(model,[6 20 1e3]);
feplot(model,def);fecom(';view3;ch8;scd.1');