API REFERENCE · V0.3.4

The whole surface area.

Every public symbol in sweep. Click any equation to see its constructor, fields, and example usage. All pages render directly from Python docstrings via mkdocstrings. Equation-class counts follow sweep.equations.list_equations(): aliases, the DAS facade and the AcousticAniso factory are not counted.

27 equation classes 2 propagators CPML boundaries torch · jax

Acoustic

8 classes

Scalar acoustic wave equations: constant density, variable density, visco-acoustic. Most-used family; default for FWI.

Acoustic

2D2nd-order

Default. Second-order in time, PML boundaries.

models: vp

Acoustic1st

2D1st-order

First-order velocity-stress formulation.

models: vp rho

Acoustic3D

3D2nd-order

3-D extension. Larger memory footprint.

models: vp

AcousticVRZ · AcousticVRZ3D

2D + 3D2nd-order

Variable density via vertical impedance perturbation.

models: vp z

AcousticLSRTM

2DBorn

LSRTM-aware acoustic; mp reflectivity perturbation field.

models: vp mp

AcousticLSRTM3D

3DBorn

3-D extension of LSRTM-aware acoustic.

models: vp mp

ViscoAcoustic

2D2nd-order

Nearly constant-Q visco-acoustic (Zhu & Harris 2014).

models: vp Q ω

Elastic

2 classes

Particle velocities and stresses. Required for converted-wave physics.

Elastic

2D1st-order

Staggered-grid velocity-stress.

models: vp vs rho

Elastic3D

3D1st-order

3-D staggered grid.

models: vp vs rho

Anisotropic

4 classes

TTI elastic media with rotated symmetry axis. Required when tilted shales / layering matter.

ElasticTTI

2Drotated staggered

Rotated staggered-grid TTI elastic.

models: vp0 vs0 rho ε δ γ θ φ

ElasticTTISG

2Dstaggered

Axis-aligned staggered-grid TTI elastic.

models: vp0 vs0 rho ε δ γ θ φ

ElasticTTISG3D

3Dstaggered

3-D axis-aligned staggered-grid TTI elastic; 21 Bond-rotated stiffnesses.

models: vp0 vs0 rho ε δ γ θ φ

ElasticTTI2nd

2D2nd-order

Displacement-based TTI elastic (Oh et al. 2020).

models: vh vs rho ε η θ

DAS family

4 classes + facade

Distributed-acoustic-sensing strain / strain-rate operators on top of the elastic wavefield. Two formulations, Zhao and Mu, each 2D + 3D, behind the DAS facade (method="zhao" or "mu"). DASElastic / DASElastic3D and DASModeler are aliases.

DAS · DASZhao · DASMu

2D + 3Dstrain

Both DAS formulations and the facade on one page — same source field, different strain output.

models: vp vs rho

Other equations

9 classes + factory

Curvilinear-grid topography, vector reflectivity (VRR) and the anisotropic (VTI / TTI) acoustic family, with its AcousticAniso factory.

Curvilinear · VRR · VTI / TTI

2D + 3D

AcousticCurvilinear, ElasticCurvilinear, AcousticVRR, ElasticVRR, AcousticVTI, AcousticTTI, AcousticTariq, AcousticVTI1st, AcousticVTI1st3D. Compiled impl='c' kernels only for ElasticVRR and AcousticVTI1st / 3D.

factory: AcousticAniso

Operators

3 classes

Spatial-derivative operators the equations are built on; rarely instantiated directly.

LaplaceGradientOps · StaggeredDerivative · RSGDerivative

torch · jax

Laplacian / gradient bundle, staggered-grid and rotated-staggered-grid first derivatives.

used by: SecondOrderEquation FirstOrderEquation

Propagators

2 classes + options

Wrap any equation into a callable solver. Equation-agnostic; same API for every physics family above.

PropTorch

torcheager + c

PyTorch backend. Eager + compiled CUDA paths.

options: memory= EagerOptions CUDAOptions

PropJax

jaxjit

JAX backend. Functional, jit'd, pmap-friendly.

options: memory= scan_unroll

Full · BoundarySaving · Ckpt

memory=every impl

Gradient-memory strategies, plus the eager / CUDA option blocks and their defaults.

options: EagerOptions CUDAOptions

Parallel

2 classes

Split one model across GPUs — a tile per rank, a halo exchange per step. Shot-parallel DDP needs nothing from here.

ModelParallel

torchnccl

Wraps a PropTorch; tiles, halos and gradients are automatic.

helpers: pad_to_mesh gather_record

MeshTopology

py × pxshot groups

The rank grid: tile coordinates, neighbours, shot groups.

guide: Domain decomposition