From af5d23892c701b858799a698bfadac746ac31ac7 Mon Sep 17 00:00:00 2001
From: EnricoTrizio <enricotrizio@gmail.com>
Date: Thu, 14 Nov 2024 09:54:13 +0100
Subject: [PATCH] Fixed metadata initialization

---
 mlcolvar/data/dataset.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/mlcolvar/data/dataset.py b/mlcolvar/data/dataset.py
index 72b7692..1fa1bdc 100644
--- a/mlcolvar/data/dataset.py
+++ b/mlcolvar/data/dataset.py
@@ -45,6 +45,10 @@ def __init__(self, dictionary: dict=None, feature_names = None, metadata: dict =
         if len(dictionary) == 0:
             raise ValueError("Empty datasets are not supported")
 
+        # initialize metadata as dict
+        if metadata is None:
+            metadata = {}
+
         # convert to torch.Tensors
         for key, val in dictionary.items():
             if not isinstance(val, torch.Tensor):