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Thermodynamic HypergRaphical Model Library (THRML)¤

THRML is a JAX library for building and sampling probabilistic graphical models, with a focus on efficient block Gibbs sampling and energy-based models. Extropic is developing hardware to make sampling from certain classes of discrete PGMs massively more energy‑efficient; THRML provides GPU‑accelerated tools for block sampling on sparse, heterogeneous graphs, making it a natural place to prototype today and experiment with future Extropic hardware.

Features include:

  • Block Gibbs sampling for PGMs
  • Arbitrary PyTree node states
  • Support for heterogeneous graphical models
  • Discrete EBM utilities (Ising/RBM‑like)
  • Enables early experimentation with future Extropic hardware

Installation¤

Requires >=python 3.10

pip install thrml

or

uv pip install thrml

For installing from the source:

git clone https://github.com/extropic-ai/thrml
cd thrml
pip install -e .

or

git clone https://github.com/extropic-ai/thrml
cd thrml
uv pip install -e .

Quick example¤

Sampling a small Ising chain with two‑color block Gibbs:

import jax
import jax.numpy as jnp
from thrml import SpinNode, Block, SamplingSchedule, sample_states
from thrml.models import IsingEBM, IsingSamplingProgram, hinton_init

nodes = [SpinNode() for _ in range(5)]
edges = [(nodes[i], nodes[i+1]) for i in range(4)]
biases = jnp.zeros((5,))
weights = jnp.ones((4,)) * 0.5
beta = jnp.array(1.0)
model = IsingEBM(nodes, edges, biases, weights, beta)

free_blocks = [Block(nodes[::2]), Block(nodes[1::2])]
program = IsingSamplingProgram(model, free_blocks, clamped_blocks=[])

key = jax.random.key(0)
k_init, k_samp = jax.random.split(key, 2)
init_state = hinton_init(k_init, model, free_blocks, ())
schedule = SamplingSchedule(n_warmup=100, n_samples=1000, steps_per_sample=2)

samples = sample_states(k_samp, program, schedule, init_state, [], [Block(nodes)])