Update element_array_ephys/export/nwb/nwb.py

Co-authored-by: Dimitri Yatsenko <dimitri@datajoint.com>

Author: bendichter

element_array_ephys/export/nwb/nwb.py

@@ -50,7 +50,7 @@ def __init__(self, lfp_electrodes_query, chunk_length: int = 10000):
             self.lfp_electrodes_query & dict(electrode=self.electrodes[0])
         ).fetch1(as_dict=True)
 
-        self.n_channels = len(lfp_electrodes_query)
+        self.n_channels = len(self.electrodes)
         self.n_tt = len(first_record["lfp"])
         self._dtype = first_record["lfp"].dtype