changing the way the file is loaded

quapy/method/_bayesian.py

@@ -2,6 +2,7 @@
 Utility functions for `Bayesian quantification <https://arxiv.org/abs/2302.09159>`_ methods.
 """
 import numpy as np
+import importlib.resources
 
 try:
     import jax
@@ -82,6 +83,9 @@ def sample_posterior(
 
 
 
+def load_stan_file():
+    return importlib.resources.files('quapy.method').joinpath('stan/pq.stan').read_text(encoding='utf-8')
+
 def pq_stan(stan_code, n_bins, pos_hist, neg_hist, test_hist, number_of_samples, num_warmup, stan_seed):
     """
     Perform Bayesian prevalence estimation using a Stan model for probabilistic quantification.

quapy/method/confidence.py

@@ -624,8 +624,7 @@ class PQ(AggregativeSoftQuantifier, BinaryAggregativeQuantifier):
         self.num_samples = num_samples
         self.region = region
         self.stan_seed = stan_seed
-        with open('quapy/method/stan/pq.stan', 'r') as f:
+        self.stan_code = _bayesian.load_stan_file()
-            self.stan_code = str(f.read())
 
     def aggregation_fit(self, classif_predictions, labels):
         y_pred = classif_predictions[:, self.pos_label]

setup.py

@@ -124,7 +124,7 @@ setup(
     # Similar to `install_requires` above, these must be valid existing
     # projects.
     extras_require={  # Optional
-       'bayes': ['jax', 'jaxlib', 'numpyro'],
+       'bayes': ['jax', 'jaxlib', 'numpyro', 'pystan'],
        'neural': ['torch'],
        'tests': ['certifi'],
        'docs' : ['sphinx-rtd-theme', 'myst-parser'],