quency</td>
</tr>
<tr class="even">
<td>bfen</td>
<td>Euclidean norm of the band-pass filtered signals</td>
<td>Average</td>
<td>do.bfz</td>
<td>Frequency</td>
</tr>
<tr class="odd">
<td>zcx</td>
<td>Zero crossing count x-axis (see notes below)</td>
<td>Sum</td>
<td>do.zcx</td>
<td>Frequency</td>
</tr>
<tr class="even">
<td>zcy</td>
<td>Zero crossing count y-axis (see notes below)</td>
<td>Sum</td>
<td>do.zcy</td>
<td>Frequency</td>
</tr>
<tr class="odd">
<td>zcz</td>
<td>Zero crossing count z-axis (see not