Boundary conditions using notebook

Get a user parameter defined in the GUI notebook.

To access a notebook-defined variable when defining boundary conditions, a callback function of the type of type cs_dof_func_t can be defined, such as the following (for a notebook variable named "t_inlet"):

static void
_notebook_t_inlet(cs_lnum_t         n_elts,
                  const cs_lnum_t  *elt_ids,
                  bool              dense_output,
                  void             *input,
                  cs_real_t        *retval)
{
  /* Get a user parameter defined in the GUI notebook */
 
  cs_real_t t_bnd = cs_notebook_parameter_value_by_name("t_inlet");
 
  /* Apply values at selected locations */
 
  for (cs_lnum_t i = 0; i < n_elts; i++) {
    const cs_lnum_t  face_id = (elt_ids == NULL) ? i : elt_ids[i];
    const cs_lnum_t  j = dense_output ? i : face_id;
    retval[j] = t_bnd;
  }
}

Note that accessing the notebook value in the function above is done through the call to cs_notebook_parameter_value_by_name.

The callback function can then be assigned to the zone named "inlet" for variable "scalar1" in the usual way (in cs_user_boundary_conditions_setup):

    cs_equation_param_t  *eqp = cs_equation_param_by_name("scalar_1");
 
    cs_equation_add_bc_by_dof_func(eqp,
                                   CS_PARAM_BC_DIRICHLET,
                                   "inlet",                // zone name
                                   cs_flag_boundary_face,  // location flag
                                   _notebook_t_inlet,      // callback function
                                   NULL);                  // input structure