How to plot multiple points at single time step?

[dc217863]

Hi,
I am using ROS and have the following use case:

Points.msg:
std_msgs/Header header
float64[] x
float64[] y

I have a topic containing multiple x, y points in a single message. I would like to plot all the x,y points at a particular time step. At the next time step I have new x,y points I would like to plot.

Is this possible with PlotJuggler? I understand that I have to create a plugin to parse the data from the messages as I want it. However, I need some guidance to understand whether it is possible to plot multiple points at a single timestep.

Thanks!

[dc217863]

I had a quick look at the code and am currently working with the following idea:
create a plugin to parse the information from the msg and add it to the series (similar to ros1_parsers::PoseMsgParser::parseMessageImpl()). This would lead to having multiple points at the same timestamp. This way no new data structure would be required.

However, the question remains, do points get automatically plotted if they are the same timestamp? If not, do you have a suggestion of how to go about this?

[facontidavide]

Yes, writing your own parser is certainly the most effective idea, but SDince version 3.4.x there is a new powerful mechanism to deal with this kind of data.

See https://slides.com/davidefaconti/plotjuggler-reactive-scripts/fullscreen

[Wayne-DWA]

@facontidavide Hi, I followed your slides and this answer but I always got this error when I clicked "save" the function. Is there a bug or something I did wrong? Thanks.

[facontidavide]

MutableScatterXY was renamed ScatterXY.

Tutorial updated

[Wayne-DWA]

thanks, it works