Added Warning for previously set rescale_parameters

bilby/core/prior/joint.py

@@ -332,18 +332,18 @@ def rescale(self, value, **kwargs):
         """
         if value is None:
             samp = np.array(list(self._current_unit_cube_parameter_values.values())).T
+            if len(samp.shape) == 1:
+                samp = samp.reshape(1, self.num_vars)
         else:
-            for key, val in zip(self.names, value):
-                self.set_rescale(key, val)
             samp = np.asarray(value)
-
-        if len(samp.shape) == 1:
-            samp = samp.reshape(1, self.num_vars)
-
-        if len(samp.shape) != 2:
-            raise ValueError("Array is the wrong shape")
-        elif samp.shape[1] != self.num_vars:
-            raise ValueError("Array is the wrong shape")
+            if len(samp.shape) == 1:
+                samp = samp.reshape(1, self.num_vars)
+            if len(samp.shape) != 2:
+                raise ValueError("Array is the wrong shape")
+            elif samp.shape[1] != self.num_vars:
+                raise ValueError("Array is the wrong shape")
+            for key, val in zip(self.names, samp.T):
+                self.set_rescale(key, val)
 
         samp = self._rescale(samp, **kwargs)
         for i, key in enumerate(self.names):
@@ -821,6 +821,18 @@ def rescale(self, val, **kwargs):
             the rescaled value once all parameters have been requested
         """
 
+        if self.dist.get_rescaled(self.name) is not None:
+            import warnings
+            warnings.warn(
+                f"Rescale values for {self.name} in {self.dist} have already been set, "
+                "indicating that another rescale-operation is in progress.\n"
+                "Call dist.reset_rescale() on the joint prior distribution associated "
+                "with this prior after using dist.rescale() and make sure all parameters "
+                "necessary for rescaling have been requested in PriorDict.rescale().\n"
+                "Resetting now.",
+                RuntimeWarning
+            )
+            self.dist.reset_rescale()
         self.dist.set_rescale(self.name, val)
 
         if self.dist.filled_rescale():