bootstrap_impl define_model_state_impl diagnostics_impl finish_initialization init_impl m_delta m_till_phi max_timestep_impl MohrCoulombYieldStress restart_impl set_till_friction_angle till_friction_angle till_friction_angle update_impl write_model_state_impl ~MohrCoulombYieldStress

till_friction_angle() [2/2] void pism::MohrCoulombYieldStress::till_friction_angle ( const array::Scalar &  bed_topography, array::Scalar &  result  ) private Computes the till friction angle phi as a piecewise linear function of bed elevation, according to user options. Computes the till friction angle \(\phi(x,y)\) at a location as the following increasing, piecewise-linear function of the bed elevation \(b(x,y)\). Let \[ M = (\phi_{\text{max}} - \phi_{\text{min}}) / (b_{\text{max}} - b_{\text{min}}) \] be the slope of the nontrivial part. Then \[ \phi(x,y) = \begin{cases} \phi_{\text{min}}, & b(x,y) \le b_{\text{min}}, \\ \phi_{\text{min}} + (b(x,y) - b_{\text{min}}) \,M, & b_{\text{min}} < b(x,y) < b_{\text{max}}, \\ \phi_{\text{max}}, & b_{\text{max}} \le b(x,y), \end{cases} \] where \(\phi_{\text{min}}=\)phi_min, \(\phi_{\text{max}}=\)phi_max, \(b_{\text{min}}=\)topg_min, \(b_{\text{max}}=\)topg_max. The default values are vaguely suitable for Antarctica. See src/pism_config.cdl. Definition at line 351 of file MohrCoulombYieldStress.cc. References pism::Component::m_config, pism::Component::m_grid, pism::Component::m_log, PISM_ERROR_LOCATION, and pism::array::Array::update_ghosts(). Referenced by bootstrap_impl().