Test ScatterWidget 2D

[ruaridhg]

Towards #94

• test_scatter.py: Added astronaut image and an inverted *-1 astronaut image to the viewer and made sure both image layers were selected before calling the ScatterWidget
• test_scatter.png added
• scatter.py: Added init to ScatterWidget class to allow self.updates_layers(None) to add the selected layers (shouldn't have an effect on other parts of the code?)

For ScatterWidget 2D only (still to test 3D data and FeaturesScatterWidget)
Fixes #129

[dstansby]

It looks like you're tackling two different tests in this PR (scatter and features scatter)? Iis one of them working and one of them not? If one of them is working, I'd suggest putting that in a separate PR that we can merge straight away. Then we can keep moving, and it will make this PR easier to debug as it will only be concerned with one test.

[ruaridhg]

It looks like you're tackling two different tests in this PR (scatter and features scatter)? Iis one of them working and one of them not? If one of them is working, I'd suggest putting that in a separate PR that we can merge straight away. Then we can keep moving, and it will make this PR easier to debug as it will only be concerned with one test.

Neither of them currently work, although features scatter at least can plot something (even if what it is plotting is inconsisent). I agree that they should be separate PRs so I will try to untangle them

[ruaridhg]

#137 solved inconsistent ordering problem. Partially addresses #129 with other behaviour perhaps desired

[dstansby]

Looks 👍 overall, but we want to keep the number of layers features scatter takes as input (1), and plot two different features stored on that one layer against each other.

[ruaridhg]

Made the suggested changes including reverting back the tox.ini so just requested a re-review as merging is blocked

[dstansby]

I think there's still code that can be removed here (see my suggestions)?

[ruaridhg]

I think there's still code that can be removed here (see my suggestions)?

Ah yes, got rid of the image layer now and tidying up of remaining comments

[dstansby]

One final request (sorry!), could you squash this all into one commit so we don't add any more test figures changes than we need to in the commit history when it's merged into main?

[ruaridhg]

1 last approval hopefully!

[dstansby]