Fix docstring (missing minus sign) for EuclideanTransform.

[mkcor]

Description

This is a tiny follow-up on #6840 (comment).

Not sure about 5e8e1a8: I have right-aligned the matrix coefficients because I find it more readable, but I noticed that, in the docstring for ProjectiveTransform, they seem centred rather than right-aligned or left-aligned...

Closes #7380.

Checklist

• A descriptive but concise pull request title
• Docstrings for all functions
• Unit tests
• A gallery example in ./doc/examples for new features
• Contribution guide is followed

Release note

Summarize the introduced changes in the code block below in one or a few sentences. The
summary will be included in the next release notes automatically:

Add missing minus sign in docstring of `skimage.transform.EuclideanTransform`.

[lagru]

Looks good. Happy with either way to format whitespace. :) Thanks Marianne.

[stefanv]

I think the 1 was wrong, and everything should be left-aligned, other than for signs.

[lagru]

The 1 as in the last element in the third row? If you look at the equation for rotation around the z-axis on Wikipedia, it seems to be correct.

[mkcor]

The 1 is consistent with the plain equations (also in other docstrings for transforms of the same family).

I have reverted 5e8e1a8 where I had right-aligned two matrices. I'm not sure how I should left-align

        [[a0  -b0  a1]
         [b0  a0  b1]
         [0   0    1]]

though. Either

        [[a0  -b0  a1]
         [b0  a0   b1]
         [0   0    1]]

where the matrix elements are left-aligned, period, or

        [[a0  -b0  a1]
         [b0  a0   b1]
         [0   0    1 ]]

to preserve the array structure? Thanks.

[lagru]

I think Stéfan was suggesting something like this 🤷 (aligned on letter / number, sign is ignored):

        [[a0 -b0  a1]
         [b0  a0  b1]
         [0   0   1 ]]

[mkcor]

sign is ignored

Thanks, I wouldn't have guessed.

        [[a0 -b0  a1]
         [b0  a0  b1]
         [0   0   1 ]]

Ok, done f662e90.

[mkcor]

@lagru should I label this PR 'quick win' or milestone 0.23?

[imagesc-bot]

This pull request has been mentioned on Image.sc Forum. There might be relevant details there:

https://forum.image.sc/t/is-this-a-tiny-bug-in-source-code-comment-and-document-eclidian-transform-in-skimage-trasform-geometric/94605/4

[lagru]

"Quick win" would have been appropriate I think. But I'll just merge this now, as it has been open for some time with no open concerns. It's also minor and easy to revert.

[lagru]

This way it also goes into v0.23. @jarrodmillman, let me know if I should have postponed this until after the release and I'll do so in the future with similar cases.