diff --git a/navipy/sensors/renderer.py b/navipy/sensors/renderer.py
index b537ade72de9c12ad069414becbe96efbf685de1..d87021cb6b6098287886ec76aaee1507d7e54772 100644
--- a/navipy/sensors/renderer.py
+++ b/navipy/sensors/renderer.py
@@ -67,6 +67,7 @@ class AbstractRender():
         # not exist
         self._logger.debug('render output:{}'.format(outputfile))
         dirname = os.path.dirname(outputfile)
+        # Todo empty dirname
         if not os.path.isdir(dirname):
             os.makedirs(dirname)
         # Check the file type
diff --git a/navipy/trajectories/__init__.py b/navipy/trajectories/__init__.py
index ce707c05322a74f1fce71d39b9219ef17b564cdf..924b6d87a4aeb13247b23594613149c6deacdf81 100644
--- a/navipy/trajectories/__init__.py
+++ b/navipy/trajectories/__init__.py
@@ -590,7 +590,7 @@ series.
                 b, a = signal.butter(order.loc[col], cutoff.loc[col])
                 if padlen is None:
                     padlen = 3*max(len(a), len(b))
-                if trajno_nan.shape[0] < padlen:
+                if trajno_nan.shape[0] <= padlen:
                     self.loc[indeces, col] *= np.nan
                 else:
                     if col[0] == 'location':