code: def select_traces(traces, interval, sample_rate=None):
      
      start, end = interval
      i, j = round(sample_rate * start), round(sample_rate * end)
      i, j = int(i), int(j)
      traces = traces[i:j, :]
      # traces = traces - np.mean(traces, axis=0)
      return traces
docs: Load traces in an interval (in seconds).