[Getfem-users] gmres did not converge!

[Zhenghuai Guo]

Hi, Andriy and Yves and Konstantinos,

I loaded two meshes, totally about 350000 elements.

I only added elasticity bricks:
  getfem::add_isotropic_linearized_elasticity_brick(model, mim_1, "u_1", 
"lambda_1", "mu_1");
  getfem::add_isotropic_linearized_elasticity_brick(model, mim_2, "u_2", 
"lambda_2", "mu_2");


and four pointwise_constraints (two more each mesh):
  
getfem::add_pointwise_constraints_with_multipliers(model,"u_1","point_1_1","point_1_1_unitx",
 "point_1_1_valuex");
  
getfem::add_pointwise_constraints_with_multipliers(model,"u_1","point_1_1","point_1_1_unity",
 "point_1_1_valuey");
  
getfem::add_pointwise_constraints_with_multipliers(model,"u_1","point_1_2","point_1_2_unitx",
 "point_1_2_valuex");
  
getfem::add_pointwise_constraints_with_multipliers(model,"u_1","point_1_2","point_1_2_unity",
 "point_1_2_valuey");
  
getfem::add_pointwise_constraints_with_multipliers(model,"u_2","point_2_1","point_2_1_unitx",
 "point_2_1_valuex");
  
getfem::add_pointwise_constraints_with_multipliers(model,"u_2","point_2_1","point_2_1_unity",
 "point_2_1_valuey");
  
getfem::add_pointwise_constraints_with_multipliers(model,"u_2","point_2_2","point_2_2_unitx",
 "point_2_2_valuex");
  
getfem::add_pointwise_constraints_with_multipliers(model,"u_2","point_2_2","point_2_2_unity",
 "point_2_2_valuey");

 The values for the pointwise_constraints are simply the same as -1. This means 
the two meshes should just be translated parallelly by -1 in both x and y 
direction.

My solver is 
  gmm::iteration iter(1E-9, 1, 100);
  getfem::standard_solve(model, iter);


But I get warning of not convergence:
iter   0 residual            1
 iter 500 residual  6.17288e-05
Level 2 Warning in getfem/getfem_model_solvers.h, line 127: gmres did not 
converge!

I am quite sure that my mesh looks good and have no strange shape elements. 
When I use small simply meshes, the code runs ok.
Could you please advise to me how to improve?

Regards
Zhenghuai Guo