llg3d.solvers.base

Define the base solver class.

Classes

BaseSolver([element, N, dt, Jx, Jy, Jz, dx, ...])

Abstract data base class for LLG3D solvers.

class BaseSolver(element='Cobalt', N=5000, dt=1e-14, Jx=300, Jy=21, Jz=21, dx=1e-09, T=0.0, H_ext=0.0, init_type='0', result_file='run.npz', start_averaging=4000, n_mean=1, n_profile=0, solver='numpy', precision='double', blocking=False, seed=12345, device='auto', profiling=False, verbosity='INFO', np=1)

Bases: ABC, RunParameters

Abstract data base class for LLG3D solvers.

Parameters:

• element (Literal['Cobalt', 'Iron', 'Nickel'])

• N (int)

• dt (float)

• Jx (int)

• Jy (int)

• Jz (int)

• dx (float)

• T (float)

• H_ext (float)

• init_type (Literal['0', 'dw'])

• result_file (str)

• start_averaging (int)

• n_mean (int)

• n_profile (int)

• solver (Literal['opencl', 'mpi', 'numpy', 'jax'])

• precision (Literal['single', 'double'])

• blocking (bool)

• seed (int)

• device (Literal['cpu', 'gpu', 'auto'])

• profiling (bool)

• verbosity (Literal['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL'])

• np (int)

metrics

Dictionary to store performance metrics of the simulation.

observables

Dictionary to store physical observables computed during the simulation.

records

Dictionary to store time series data recorded during the simulation, such as x profiles and time averages.

np

Number of processes (for MPI simulations).

Type:

int

np_float

Numpy dtype for floating point calculations (float32 or float64).

grid

Grid object representing the simulation domain and discretization.

elem

Element object containing the physical parameters and methods for the LLG equation.

rng

Random number generator for temperature fluctuations.

profiling_stats

Profiling stats for kernels and functions, filled during the simulation if profiling is enabled.

solver_type: ClassVar[str] = 'base'

Solver type name

theta_init_0(t)

Initialization of theta with 0.

Parameters:

t (float)

Return type:

ndarray

theta_init_dw(t)

Initialization of theta with a domain wall profile.

Parameters:

t (float)

Return type:

ndarray

phi_init(t)

Initialization of phi.

Parameters:

t (float)

Return type:

ndarray

_init_m_n()

Initialize the magnetization array at time step n.

Return type:

ndarray

_init_rng()

Initialize a random number generator for temperature fluctuations.

Returns:

A numpy random number generator

Return type:

Generator

_get_R_random()

Generate the random field for temperature fluctuations.

Returns:

Random field array (shape (3, nx, ny, nz))

Return type:

ndarray

_normalize(m_n)

Normalize the magnetization array (in place).

\[\mathbf{m}_n = \frac{\mathbf{m}_n}{|\mathbf{m}_n|}\]

Parameters:

m_n (ndarray) – Magnetization array at time step n (shape (3, nx, ny, nz)).

Return type:

None

_xyz_average(m)

Returns the spatial average of m with shape (g.dims) using the midpoint method.

Parameters:

m (ndarray) – Array to be integrated

Returns:

Spatial average of m

Return type:

float

_record_xyz_average(m_n, t, n)

Update the time average of m1.

Parameters:

• m_n (ndarray)

• t (float)

• n (int)

Return type:

None

_finalize()

Normalize m1_mean by the actual number of samples accumulated.

Return type:

None

_yz_average(m_i)

Returns the spatial average of m using the midpoint method along y and z.

Parameters:

m_i (ndarray) – Array to be integrated

Returns:

Spatial average of m in y and z of shape (g.dims[0],)

Return type:

ndarray

_update_x_profiles(m_n, t)

Update x profiles of the averaged m_i in y and z.

Parameters:

• m_n (ndarray)

• t (float)

Return type:

None

_record(m_n, t, n)

Record simulation data.

Parameters:

• m_n (Any)

• t (float)

• n (int)

Return type:

None

_progress_bar()

Return a progress bar for the given range using tqdm.

abstract _simulate()

Simulates the system for N iterations.

Returns:

Total simulation time

Return type:

total_time

run()

Runs the simulation and store the results.

Return type:

None

_format_profiling()

Format the profiling information for display.

Return type:

str

save(dir_path='.')

Saves the results of the simulation to a .npz file.

Parameters:

dir_path (str | Path) – Directory path to save the results

Return type:

None