# JAX

- Category: AI platforms
- Official site: https://jax.readthedocs.io/en/latest
- HTML: https://www.88z.ai/en/tools/jax
- Markdown: https://www.88z.ai/en/tools/jax.md

High-performance array computing with automatic differentiation for ML research

## What is JAX?

JAX is a Python library designed for high-performance array computing and automatic differentiation, catering to the rigorous speed and flexibility demands of machine learning research.By composing transformations such as grad, vmap, and jit, it converts NumPy-style code into programs that run efficiently on GPUs and TPUs, enabling developers to implement complex mathematical models with concise code.

The framework's core strength lies in its composable function transformation system, which supports forward and reverse-mode automatic differentiation, vectorization, and just-in-time (JIT) compilation.Whether building neural networks, running scientific simulations, or processing large-scale distributed data, JAX delivers near-hardware execution efficiency while maintaining the convenience of Python development.

JAX also introduces advanced kernel languages like Pallas, allowing developers to write custom high-performance operators tailored for TPUs and GPUs.Combined with its support for distributed computing and multi-controller environments, JAX has become a preferred infrastructure for many cutting-edge AI research projects and large-scale training tasks.

## Key features

- **Automatic Differ**：Provides transformations like grad and value_and_grad, supporting higher-order derivatives for complex optimization problems.
- **Just-In-Time Com**：Compiles Python functions into optimized machine code via XLA, significantly boosting execution speed on GPUs and TPUs.
- **Auto-Vectorizati**：Uses the vmap transformation to automatically map single-sample logic to batch data, simplifying parallel processing code.
- **NumPy-Compatible**：Offers the jax.numpy module, highly compatible with NumPy APIs, reducing the learning curve for migrating existing code.
- **Distributed Para**：Supports pmap and shard_map for easy implementation of data and model parallelism across multiple devices.
- **Pallas Kernel Pr**：Enables developers to write custom GPU/TPU kernels, breaking through performance bottlenecks of standard operators.

## How to use it

1. 1.Install JAX: Choose the CPU, GPU, or TPU version for pip installation based on your hardware environment.
2. 2.Import Modules: Replace standard NumPy imports with import jax.numpy as jnp.
3. 3.Define Functions: Write standard Python numerical computation functions.
4. 4.Apply Transformations: Use the @jax.jit decorator to accelerate functions, or use jax.grad to obtain gradient functions.
5. 5.Execute Computation: Call the transformed functions, and JAX will automatically handle compilation and device placement.

## Where it fits

- **Deep Learning Re**：Rapidly prototype new neural network architectures, leveraging automatic differentiation and JIT to accelerate experimental iterations.
- **Scientific Compu**：Used for physics simulations, differential equation solving, and other scenarios requiring high-precision and high-performance array operations.
- **Reinforcement Le**：Handle large-scale state space search and policy gradient calculations, utilizing vectorization to improve sampling efficiency.

## Pricing and free quota

Pricing and any free quota follow the official site.

## Who it is for

- Machine Learning Researchers
- Scientific Computing Engineers
- High-Performance Computing Developers

## FAQ

### What is the difference between JAX and NumPy?

JAX provides an API similar to NumPy but adds automatic differentiation, just-in-time compilation, and the ability to run on accelerators (GPU/TPU).

### Which hardware does JAX support?

JAX supports CPUs, NVIDIA GPUs, and Google TPUs, optimized through the XLA backend.

### What is Pallas?

Pallas is a kernel programming language within JAX that allows developers to write high-performance operators customized for specific hardware like TPUs and GPUs.

## Tags

Automatic Differentiation · High-Performance Computing

Features, pricing and availability follow the official site. Except for 88z.ai’s own API pages, this is a third-party product; 88z.ai only provides a directory introduction.