Google JAX

JAX
Developer(s)Google
Preview release
v0.4.31 / 30 July 2024; 3 months ago (2024-07-30)
Repositorygithub.com/google/jax
Written inPython, C++
Operating systemLinux, macOS, Windows
PlatformPython, NumPy
Size9.0 MB
TypeMachine learning
LicenseApache 2.0
Websitejax.readthedocs.io/en/latest/ Edit this on Wikidata

Google JAX is a machine learning framework for transforming numerical functions.[1][2][3] It is described as bringing together a modified version of autograd (automatic obtaining of the gradient function through differentiation of a function) and TensorFlow's XLA (Accelerated Linear Algebra). It is designed to follow the structure and workflow of NumPy as closely as possible and works with various existing frameworks such as TensorFlow and PyTorch.[4][5] The primary functions of JAX are:[1]

  1. grad: automatic differentiation
  2. jit: compilation
  3. vmap: auto-vectorization
  4. pmap: Single program, multiple data (SPMD) programming

grad

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The below code demonstrates the grad function's automatic differentiation.

# imports from jax import grad import jax.numpy as jnp  # define the logistic function def logistic(x):       return jnp.exp(x) / (jnp.exp(x) + 1)  # obtain the gradient function of the logistic function grad_logistic = grad(logistic)  # evaluate the gradient of the logistic function at x = 1  grad_log_out = grad_logistic(1.0)    print(grad_log_out) 

The final line should outputː

0.19661194 

jit

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The below code demonstrates the jit function's optimization through fusion.

# imports from jax import jit import jax.numpy as jnp  # define the cube function def cube(x):     return x * x * x  # generate data x = jnp.ones((10000, 10000))  # create the jit version of the cube function jit_cube = jit(cube)  # apply the cube and jit_cube functions to the same data for speed comparison cube(x) jit_cube(x) 

The computation time for jit_cube (line #17) should be noticeably shorter than that for cube (line #16). Increasing the values on line #7, will further exacerbate the difference.

vmap

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The below code demonstrates the vmap function's vectorization.

# imports from jax import vmap partial import jax.numpy as jnp  # define function def grads(self, inputs):     in_grad_partial = jax.partial(self._net_grads, self._net_params)     grad_vmap = jax.vmap(in_grad_partial)     rich_grads = grad_vmap(inputs)     flat_grads = np.asarray(self._flatten_batch(rich_grads))     assert flat_grads.ndim == 2 and flat_grads.shape[0] == inputs.shape[0]     return flat_grads 

The GIF on the right of this section illustrates the notion of vectorized addition.

Illustration video of vectorized addition

pmap

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The below code demonstrates the pmap function's parallelization for matrix multiplication.

# import pmap and random from JAX; import JAX NumPy from jax import pmap, random import jax.numpy as jnp  # generate 2 random matrices of dimensions 5000 x 6000, one per device random_keys = random.split(random.PRNGKey(0), 2) matrices = pmap(lambda key: random.normal(key, (5000, 6000)))(random_keys)  # without data transfer, in parallel, perform a local matrix multiplication on each CPU/GPU outputs = pmap(lambda x: jnp.dot(x, x.T))(matrices)  # without data transfer, in parallel, obtain the mean for both matrices on each CPU/GPU separately means = pmap(jnp.mean)(outputs) print(means) 

The final line should print the valuesː

[1.1566595 1.1805978] 

See also

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References

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  1. ^ a b Bradbury, James; Frostig, Roy; Hawkins, Peter; Johnson, Matthew James; Leary, Chris; MacLaurin, Dougal; Necula, George; Paszke, Adam; Vanderplas, Jake; Wanderman-Milne, Skye; Zhang, Qiao (2022-06-18), "JAX: Autograd and XLA", Astrophysics Source Code Library, Google, Bibcode:2021ascl.soft11002B, archived from the original on 2022-06-18, retrieved 2022-06-18
  2. ^ Frostig, Roy; Johnson, Matthew James; Leary, Chris (2018-02-02). "Compiling machine learning programs via high-level tracing" (PDF). MLsys: 1–3. Archived (PDF) from the original on 2022-06-21.{{cite journal}}: CS1 maint: date and year (link)
  3. ^ "Using JAX to accelerate our research". www.deepmind.com. Archived from the original on 2022-06-18. Retrieved 2022-06-18.
  4. ^ Lynley, Matthew. "Google is quietly replacing the backbone of its AI product strategy after its last big push for dominance got overshadowed by Meta". Business Insider. Archived from the original on 2022-06-21. Retrieved 2022-06-21.
  5. ^ "Why is Google's JAX so popular?". Analytics India Magazine. 2022-04-25. Archived from the original on 2022-06-18. Retrieved 2022-06-18.