3RNN/Lib/site-packages/opt_einsum/backends/jax.py

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2024-05-26 19:49:15 +02:00
"""
Required functions for optimized contractions of numpy arrays using jax.
"""
import numpy as np
from ..sharing import to_backend_cache_wrap
__all__ = ["build_expression", "evaluate_constants"]
_JAX = None
def _get_jax_and_to_jax():
global _JAX
if _JAX is None:
import jax
@to_backend_cache_wrap
@jax.jit
def to_jax(x):
return x
_JAX = jax, to_jax
return _JAX
def build_expression(_, expr): # pragma: no cover
"""Build a jax function based on ``arrays`` and ``expr``.
"""
jax, _ = _get_jax_and_to_jax()
jax_expr = jax.jit(expr._contract)
def jax_contract(*arrays):
return np.asarray(jax_expr(arrays))
return jax_contract
def evaluate_constants(const_arrays, expr): # pragma: no cover
"""Convert constant arguments to jax arrays, and perform any possible
constant contractions.
"""
jax, to_jax = _get_jax_and_to_jax()
return expr(*[to_jax(x) for x in const_arrays], backend='jax', evaluate_constants=True)