diff --git a/navipy/moving/agent.py b/navipy/moving/agent.py
index 196dddff687e4ea9403b7f579a7260076463ca19..a50059cd12619109736d41fda37a01077e11a354 100644
--- a/navipy/moving/agent.py
+++ b/navipy/moving/agent.py
@@ -30,6 +30,7 @@ import inspect
 import navipy.moving.maths as navimomath
 from navipy.database import DataBaseLoad
 import time
+import os
 
 version = float(nx.__version__)
 
@@ -392,6 +393,8 @@ the agent motion, or
                            timeout=1,
                            filename=None,
                            blocksize=100):
+        if os.path.exist(filename):
+            self.velocities = pd.read_hdf()
         nodes_tocompute = self.velocities.isna().any(axis=1)
         nodes_tocompute = nodes_tocompute[nodes_tocompute].index
         # Build a list of nodes