I know that I can use an empty array to clean up the chart. But the cleaned chart has no coordinates. Can I leave the coordinates? And in the begining, there is also no coordinates.
How can I do that the line chart has coordinates in the begining even I don't have any point. Is it possible?
If you set msg.payload = null; then that should "plot" a non-existent point. So as long as you have set the axis min and max it should create the chart for you. If you send one null for each topic you wish to display it will also populate the legend for you.