Check if there is an attribute before trying to access it (#851)

* Check if there is an attribute before trying to access it

* Code format

* Pin versions of jax dependencies

* Make ordinal families work with intercept only models

bambi/families/univariate.py

@@ -220,8 +220,17 @@ def transform_backend_eta(eta, kwargs):
         # shape(threshold) = (K, )
         # shape(eta) = (n, )
         # shape(threshold - shape_padright(eta)) = (n, K)
+
         threshold = kwargs["threshold"]
-        eta_shifted = threshold - pt.shape_padright(eta)
+
+        # When the model does not have any predictors.
+        # Inference can be slower, as this can potentially build a larger object.
+        # However, this is needed for consistency with other parts of the codebase
+        if eta == 0:
+            eta_shifted = threshold - pt.shape_padright(pt.zeros(len(kwargs["observed"])))
+        else:
+            eta_shifted = threshold - pt.shape_padright(eta)
+
         return eta_shifted
 
     @staticmethod
@@ -393,8 +402,17 @@ def transform_backend_eta(eta, kwargs):
         # shape(threshold) = (K, )
         # shape(eta) = (n, )
         # shape(threshold - shape_padright(eta)) = (n, K)
+
         threshold = kwargs["threshold"]
-        eta_shifted = threshold - pt.shape_padright(eta)
+
+        # When the model does not have any predictors.
+        # Inference can be slower, as this can potentially build a larger object.
+        # However, this is needed for consistency with other parts of the codebase
+        if eta == 0:
+            eta_shifted = threshold - pt.shape_padright(pt.zeros(len(kwargs["observed"])))
+        else:
+            eta_shifted = threshold - pt.shape_padright(eta)
+
         return eta_shifted
 
     @staticmethod

bambi/priors/scaler.py

@@ -55,11 +55,19 @@ def scale_response(self):
         # Here we would add cases for other families if we wanted
         if isinstance(self.model.family, (Gaussian, StudentT)):
             sigma = self.model.components["sigma"]
-            if isinstance(sigma, ConstantComponent) and sigma.prior.auto_scale:
+            if (
+                isinstance(sigma, ConstantComponent)
+                and hasattr(sigma.prior, "auto_scale")  # not available when `.prior` is a scalar
+                and sigma.prior.auto_scale
+            ):
                 sigma.prior = Prior("HalfStudentT", nu=4, sigma=self.response_std)
         elif isinstance(self.model.family, VonMises):
             kappa = self.model.components["kappa"]
-            if isinstance(kappa, ConstantComponent) and kappa.prior.auto_scale:
+            if (
+                isinstance(kappa, ConstantComponent)
+                and hasattr(kappa.prior, "auto_scale")  # not available when `.prior` is a scalar
+                and kappa.prior.auto_scale
+            ):
                 kappa.prior = Prior("HalfStudentT", nu=4, sigma=self.response_std)
 
     def scale_intercept(self, term):

pyproject.toml

@@ -23,7 +23,7 @@ dependencies = [
     "formulae>=0.5.3",
     "graphviz",
     "pandas>=1.0.0",
-    "pymc>=5.16.1",
+    "pymc>=5.18.0",
 ]
 
 [project.optional-dependencies]
@@ -38,8 +38,12 @@ dev = [
     "seaborn>=0.9.0",
 ]
 
+# TODO: Unpin this before making a release
 jax = [
-    "bayeux-ml>=0.1.13",
+    "bayeux-ml==0.1.14",
+    "blackjax==1.2.3",
+    "jax<=0.4.33",
+    "jaxlib<=0.4.33",
 ]
 
 [project.urls]
@@ -50,14 +54,14 @@ changelog = "https://github.com/bambinos/bambi/blob/main/docs/CHANGELOG.md"
 
 [tool.setuptools]
 packages = [
-    "bambi", 
-    "bambi.backend", 
-    "bambi.data", 
-    "bambi.defaults", 
+    "bambi",
+    "bambi.backend",
+    "bambi.data",
+    "bambi.defaults",
     "bambi.families",
-    "bambi.interpret", 
-    "bambi.priors", 
-    "bambi.terms", 
+    "bambi.interpret",
+    "bambi.priors",
+    "bambi.terms",
 ]
 
 [tool.black]