np.math is deprecated call to math

Author: zm711

neo/rawio/blackrockrawio.py

@@ -646,7 +646,7 @@ def _get_timestamp_slice(self, timestamp, seg_index, t_start, t_stop):
         if t_start is None:
             ind_start = None
         else:
-            ts = np.math.ceil(t_start * self.__nev_basic_header['timestamp_resolution'])
+            ts = int(np.ceil(t_start * self.__nev_basic_header['timestamp_resolution']))
             ind_start = np.searchsorted(timestamp, ts)
 
         if t_stop is None: