Merge pull request #335 from anevolbap/issue_329-IV-fit-method

Fix #329: Add `random_seed` to the `fit` method.

Author: drbenvincent

causalpy/pymc_models.py

@@ -110,7 +110,7 @@ def _data_setter(self, X) -> None:
             pm.set_data({"X": X})
 
     def fit(self, X, y, coords: Optional[Dict[str, Any]] = None) -> None:
-        """Draw samples fromposterior, prior predictive, and posterior predictive
+        """Draw samples from posterior, prior predictive, and posterior predictive
         distributions, placing them in the model's idata attribute.
         """
 
@@ -380,12 +380,19 @@ def fit(self, X, Z, y, t, coords, priors):
         """Draw samples from posterior, prior predictive, and posterior predictive
         distributions.
         """
+
+        # Ensure random_seed is used in sample_prior_predictive() and
+        # sample_posterior_predictive() if provided in sample_kwargs.
+        random_seed = self.sample_kwargs.get("random_seed", None)
+
         self.build_model(X, Z, y, t, coords, priors)
         with self:
             self.idata = pm.sample(**self.sample_kwargs)
-            self.idata.extend(pm.sample_prior_predictive())
+            self.idata.extend(pm.sample_prior_predictive(random_seed=random_seed))
             self.idata.extend(
-                pm.sample_posterior_predictive(self.idata, progressbar=False)
+                pm.sample_posterior_predictive(
+                    self.idata, progressbar=False, random_seed=random_seed
+                )
             )
         return self.idata