# Numpyro sampler

**URL:** <https://discourse.pymc.io/t/numpyro-sampler/16211>\
**Category:** version agnostic\
**Created:** [December 4, 2024, 6:26pm UTC](https://discourse.pymc.io/t/numpyro-sampler/16211 "2024-12-04T18:26:05Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![cosine](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.pymc.io/cosine/32/8777_2.png) [@cosine](https://discourse.pymc.io/u/cosine)\
**Post date:** [December 4, 2024, 6:26pm UTC](https://discourse.pymc.io/t/numpyro-sampler/16211/1 "2024-12-04T18:26:05Z")

</div>

Hi,  
I’m trying to use the numpyro sampler, but I get the error below.

Are there any recent working examples?  
Or otherwise insight in what is wrong?

```python
 173 trace =pm.sampling.jax.sample_numpyro_nuts(dXfit, chains=4)

File ~/anaconda3/envs/pymc_env/lib/python3.12/site-packages/pymc/sampling/jax.py:611, in sample_jax_nuts(draws, tune, chains, target_accept, random_seed, initvals, jitter, model, var_names, nuts_kwargs, progressbar, keep_untransformed, chain_method, postprocessing_backend, postprocessing_vectorize, postprocessing_chunks, idata_kwargs, compute_convergence_checks, nuts_sampler)
    608 raise ValueError(f"{nuts_sampler=} not recognized")
    610 tic1 = datetime.now()
--> 611 raw_mcmc_samples, sample_stats, library = sampler_fn(
    612 model=model,
    613 target_accept=target_accept,
    614 tune=tune,
    615 draws=draws,
    616 chains=chains,
    617 chain_method=chain_method,
    618 progressbar=progressbar,
    619 random_seed=random_seed,
    620 initial_points=initial_points,
    621 nuts_kwargs=nuts_kwargs,
    622 )
    623 tic2 = datetime.now()
    625 if idata_kwargs is None:

File ~/anaconda3/envs/pymc_env/lib/python3.12/site-packages/pymc/sampling/jax.py:437, in _sample_numpyro_nuts(model, target_accept, tune, draws, chains, chain_method, progressbar, random_seed, initial_points, nuts_kwargs)
    429 nuts_kwargs.setdefault("dense_mass", False)
    431 nuts_kernel = NUTS(
    432 potential_fn=logp_fn,
    433 target_accept_prob=target_accept,
    434 **nuts_kwargs,
    435 )
--> 437 pmap_numpyro = MCMC(
    438 nuts_kernel,
    439 num_warmup=tune,
    440 num_samples=draws,
    441 num_chains=chains,
    442 postprocess_fn=None,
    443 chain_method=chain_method,
    444 progress_bar=progressbar,
    445 )
    447 map_seed = jax.random.PRNGKey(random_seed)
    448 if chains > 1:

File ~/anaconda3/envs/pymc_env/lib/python3.12/site-packages/numpyro/infer/mcmc.py:382, in MCMC. __init__ (self, sampler, num_warmup, num_samples, num_chains, thinning, postprocess_fn, chain_method, progress_bar, jit_model_args)
    380 self._cache = {}
    381 self._collection_params = {}
--> 382 self._set_collection_params()

File ~/anaconda3/envs/pymc_env/lib/python3.12/site-packages/numpyro/infer/mcmc.py:514, in MCMC._set_collection_params(self, lower, upper, collection_size, phase)
    509 def _set_collection_params(
    510 self, lower=None, upper=None, collection_size=None, phase=None
    511 ):
    512 self._collection_params["lower"] = self.num_warmup if lower is None else lower
    513 self._collection_params["upper"] = (
--> 514 self.num_warmup + self.num_samples if upper is None else upper
    515 )
    516 self._collection_params["collection_size"] = collection_size
    517 self._collection_params["phase"] = phase

TypeError: unsupported operand type(s) for +: 'int' and 'Model'

```

---

<div class="post-metadata">

**Author:** ![ricardoV94](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.pymc.io/ricardov94/32/5775_2.png) [@ricardoV94](https://discourse.pymc.io/u/ricardoV94)\
**Post date:** [December 4, 2024, 7:26pm UTC](https://discourse.pymc.io/t/numpyro-sampler/16211/2 "2024-12-04T19:26:17Z")

</div>

Try to use pm.sample with `pm.sample(nuts_sampler="numpyro")` and make sure you’re on a recent version of pymc