Choose a learning backend

PyTorch is the default learning path. The JAX backend fits into an existing JAX, Equinox, and Optax stack and supports static-shape compilation.

Use PyTorch (the default)

The top-level imports resolve to the PyTorch backend, so you get the most direct path from build_graph to GNS to train, as the mesh-to-emulator guide shows. Warp’s automatic differentiation integrates directly through torch.autograd.Function.

Use JAX when your stack already uses it

Switch to the JAX/Equinox backend when the surrounding analysis already depends on JAX, Equinox, or Optax, or when you need static-shape compilation. Reach it through explicit imports:

from waxmorph.jax.gnn import GNS
from waxmorph.jax.graph import build_graph
from waxmorph.jax.losses import make_sinkhorn_loss
from waxmorph.jax.train import TrainConfig, train

JAX model construction uses an explicit PRNG key. Its graph builder always returns the observed edge count as a fourth value. Supplying max_edges pads the edge arrays to that capacity for stable compiled shapes; the default returns edge arrays sized to the observed graph:

from waxmorph.jax import build_graph

node_features, edge_index, edge_features, num_edges = build_graph(
    X, P, R, particle_count, c=c, max_edges=max_edges
)

PyTorch training takes a mutable optimizer and restores it to the selected best model. JAX training takes an Optax transformation and optimizer state; TrainResult contains the selected model and log, while callers manage Optax state separately.

Note

JAX training bounds directed edges and neighbor pairs by N * max_edges_factor and raises on overflow. Its Warp mechanics and diffusion custom VJPs run on CUDA; CPU training uses zero for both prescribed step counts. PyTorch accepts supported Torch/Warp CPU or CUDA devices.

PyTorch exposes GeomLoss Sinkhorn, MMD, and Hausdorff families. JAX exposes debiased OTT Sinkhorn divergence. See Shape losses.