Feature request: Live updating plots

[cool-RR]

It is time for the greatest VisiData feature request of all time. I've wanted this for a long time, and it's pretty ambitious so it might never get implemented, but let's put it on the table anyway.

I want to have live plots. I'm running experiments that take a while to produce output. I'm anxiously awaiting the interesting parts of their results so I could draw conculsions and run the next experiment. I want to see that progress on a plot, live. This means I want to draw a plot of a certain sheet, and then as more rows are written to that sheet, I want the plot to automatically add new points on the screen.

[midichef]

Hi @cool-RR, I submitted #2597 and #2598. Once you install both of those, you should be able to monitor your graphs with reload-every.

It was not especially complicated to implement as the basic functionality was already implemented. So imo the greatest VisiData feature request of all time is still #2: make a package for visidata.

Also, until these patches are incorporated into visidata, you may find the watch shell tool useful. Something like: watch -n 10 vd -p draw_graph.vdj

[cool-RR]

Hmm, this doesn't work for me. I checked out the develop branch and then merged your two branches. I did pip install -e . and I ran VisiData on a jsonl file that's getting new data pushed into it continuously. First I tried to use reload-modified on the sheet and draw a plot, and increased the x range expecting to see more points automatically, but I didn't. Then I went back to the sheet and tried reload-every instead which didn't work. Am I doing something wrong.

[anjakefala]

Hey @cool-RR!

To make things easier, both commits are now in develop.

The steps I would do are:
pip uninstall visidata - Make sure this is the only version of VisiData in your environment
pip install git+https://github.com:saulpw/visidata.git

And then try it out. I believe the step is to use reload-every on the underlying sheet and on the graph sheet. Let us know if you get it working!

[midichef]

Hmm, I hadn't actually tested reloading graphs while another sheet reloads from a file. That case is not working. It looks like the source sheet changes are not being reflected on the graph. I'll continue to look into it.

(My test case was a custom sheet that generates more rows over time in memory, not on disk.)

[cool-RR]

Thanks, let me know when that can be tested. Also, I think that a good UX would not require the user to go back to the source sheet and use one of the reload-* commands, but rather allow making the plot live without leaving the plot sheet. So maybe something like allowing to run the reload-* commands on the plot sheet and propagating them to the source sheet.

[cool-RR]

I recently discovered btm:

https://github.com/ClementTsang/bottom

It's like htop except it shows live updating plots of CPU usage, memory usage etc, with braille dots like VisiData. I recommend giving it a try. It's a good example of how to show a live updating plot.