Fixed log det jac computation of standardize transform

y = (x - mu) / sigma
log p(y) = log p(x) - log(sigma)

Author: han-ol

bayesflow/adapters/transforms/standardize.py

@@ -123,7 +123,7 @@ def inverse(self, data: np.ndarray, **kwargs) -> np.ndarray:
 
     def log_det_jac(self, data, inverse: bool = False, **kwargs) -> np.ndarray:
         std = np.broadcast_to(self.std, data.shape)
-        ldj = np.log(np.abs(std))
+        ldj = -np.log(np.abs(std))
         if inverse:
             ldj = -ldj
         return np.sum(ldj, axis=tuple(range(1, ldj.ndim)))