Group-By functionality for Scatter Widget

[aak65]

This is an improved grouping function for the Scatter plot that works faster and gets less confused. I thought it may be beneficial to have this as a separate pull from the time series stuff.

[ChrisBeaumont]

2 quick comments:

• You have an emacs-saved backup file (scatterwidget.ui~) in this PR, which you'll want to remove.
• As I mentioned in Date-Time Support for Scatter Plot #565, I think it's best to implement this feature (which is really cool) as a custom scatterwidget subclass, probably stored with the plugins. Like what @astrofrog has been working on in Move all ginga widget code to a self-contained plugin #585. We'd like to start emphasizing putting new functionality in plugins/custom viewers, and then pulling particular features into the "standard" viewers more slowly. It shouldn't be much work to adapt your PR to do this, let us know if you get stuck

[aak65]

Sure thing; I'll definitely give it a shot!

[astrofrog]

@aak65 - just for information, I've merged in the pull request #590 which improves how we deal with plug-in functionality, and the documentation here:

http://www.glueviz.org/en/latest/python_guide/customization.html

has been updated. To add this as a plugin in glue, you simply need to add a file in glue/plugins inside which you define a class that inherits from ScatterWidget and overloads it appropriately. Then in your config.py file you can do:

from glue.config import qt_client
qt_client.add(MyScatterWidget)

and it should appear in the list of options. We can then see whether to enable it as a default plug-in. Let me know if you have any questions or need any help!

(you will need to rebase to get the latest plugin stuff)

[aak65]

@astrofrog Thanks for that information! It's very helpful and I think I can figure this out. I'll work on it and update the PR once it's working so you guys can see if it meshes well.

Been a bit caught up with finals, but I'll have something up soon.

[astrofrog]

@aak65 - just to check, what is the status of this pull request?

[aak65]

@astrofrog - Sorry for the radio silence. I just graduated, moved across the country, and started a new job (my first real job). I really need to devote my full attention to settling in at the moment. In all honesty I may not come back to glue for a little while.

[astrofrog]

I'm going to close this since the scatter widget code has now been completely re-written, but hopefully this would be simpler to implement with the new viewer code.

@aak65 - if you are interested in porting over your code to the new viewers, just email me or reach out to me on Slack (you can get an invite here: https://glueviz-slack-invite.herokuapp.com/)