<td> smoothed line, while smooth is true, lineStyle.type can not be dashed.
</tr>
<tr>
<td><b>{boolean}</b> dataFilter </td>
<td> 'nearst' </td>
<td> line </td>
<td> ECharts will optimize for the situation when data number is much larger than viewport width. It will filter the data showed in one pixel width. And this option is for data filtering strategy.<br/>