Linting

src/skmatter/preprocessing/_data.py

@@ -528,9 +528,11 @@ def fit(self, Knm, Kmm, y=None, sample_weight=None):
             # but has been changed to Knm.T @ Knm @ Kmm^{-1} to avoid the memory
             # overload often caused by storing n x n matrices. This is fine
             # for the following trace, but should not be used for other operations.
-            Khat_trace = np.trace(Knm_centered.T @ Knm_centered @ np.linalg.pinv(Kmm, self.rcond))
+            Khat_trace = np.trace(
+                Knm_centered.T @ Knm_centered @ np.linalg.pinv(Kmm, self.rcond)
+            )
 
-            self.scale_ = np.sqrt(np.trace(Khat) / Knm.shape[0])
+            self.scale_ = Khat_trace / Knm.shape[0]
         else:
             self.scale_ = 1.0