`specfem::point::attenuation`¶

template<specfem::element::dimension_tag DimensionTag, specfem::element::medium_tag MediumTag, specfem::element::attenuation_tag AttenuationTag, bool UseSIMD> struct attenuation¶

Combined attenuation struct for viscoelastic simulations.

Merges attenuation_factors and memory_variable into a single type that carries both the constant-Q relaxation coefficients and the per-SLS memory variable arrays. Using one struct eliminates the need to pass the two separate objects everywhere they are consumed together.

Template Parameters:

DimensionTag – Spatial dimension (dim2 or dim3)
MediumTag – Medium type (elastic)
AttenuationTag – Attenuation model (constant_isotropic)
UseSIMD – Enable SIMD vectorization

Dimension-specific Specializations¶

2D PSV Elastic Medium with Constant Isotropic Attenuation¶

template<bool UseSIMD> struct attenuation<specfem::element::dimension_tag::dim2, specfem::element::medium_tag::elastic_psv, specfem::element::attenuation_tag::constant_isotropic, UseSIMD> : public specfem::data_access::Accessor<specfem::datatype::AccessorType::point, specfem::data_access::DataClassType::attenuation, specfem::element::dimension_tag::dim2, UseSIMD>¶

Attenuation state for 2D elastic medium with constant isotropic Q.

Stores the Runge-Kutta integration factors together with the three independent 2D memory variable components (Rxx, Rxz, Rkappa).

Template Parameters:: UseSIMD – Enable SIMD vectorization

Public Functions

inline attenuation()¶: Default constructor — zeroes all R fields; factor fields default.

Full value constructor.

Parameters:

kappa_relaxation_rate – Scaling factor for kappa attenuation
mu_relaxation_rate – Scaling factor for mu attenuation
alpha_rk – Runge-Kutta alpha factors (per SLS)
beta_rk – Runge-Kutta beta factors (per SLS)
gamma_rk – Runge-Kutta gamma factors (per SLS)
Rxx – Memory variable R_xx
Rxz – Memory variable R_xz
Rkappa – Memory variable R_kappa
epsilon_xx – Stored symmetrised strain ε_xx
epsilon_zz – Stored symmetrised strain ε_zz
epsilon_xz – Stored symmetrised strain ε_xz

inline void init()¶: Zero all memory variable (R) fields and symmetrised strain.

inline attenuation operator+(const attenuation &rhs) const¶: Component-wise addition on R fields and epsilon; RK/common factors copied.

inline attenuation &operator+=(const attenuation &rhs)¶: In-place addition on R fields and epsilon.

inline attenuation operator*(const type_real &rhs) const¶: Scalar multiplication on R fields and epsilon; RK/common factors copied.

inline bool operator==(const attenuation &other) const¶: Equality — compares all fields (factors, R, and epsilon).

inline std::string print() const¶: String representation (non-SIMD only).

Public Members

value_type alpha_rk¶: Runge-Kutta coefficients; one entry per SLS mechanism (computed from tau_sigma and deltat; constant throughout a run).

datatype epsilon_xx¶: ε_xx = ∂u_x/∂x (previous Taylor-step)

datatype epsilon_zz¶: ε_zz = ∂u_z/∂z (previous Taylor-step)

datatype epsilon_xz¶: ε_xz = ½(∂u_x/∂z + ∂u_z/∂x) (previous Taylor-step)

3D Elastic Medium with Constant Isotropic Attenuation¶

template<bool UseSIMD> struct attenuation<specfem::element::dimension_tag::dim3, specfem::element::medium_tag::elastic, specfem::element::attenuation_tag::constant_isotropic, UseSIMD> : public specfem::data_access::Accessor<specfem::datatype::AccessorType::point, specfem::data_access::DataClassType::attenuation, specfem::element::dimension_tag::dim3, UseSIMD>¶

Attenuation state for 3D elastic medium with constant isotropic Q.

Stores the Runge-Kutta integration factors together with the six independent 3D memory variable components (Rxx, Ryy, Rxy, Rxz, Ryz, Rkappa).

Template Parameters:: UseSIMD – Enable SIMD vectorization