Integration of CalcDeltaImpact class of unsequa into develop

[simonameiler]

Changes proposed in this PR:

• Integration of CalcDeltaImpact class of unsequa into develop
• Update unsequa tutorial
• Modification of plotting functionalities of the uncertainty output in unc_output to skip columns of the uncertainty output dataframe which are zeros or nan.
• addition of a small function called save_divide in util which handles division by zero and NaN values in the numerator or denominator. This is needed for the relative impact change calculation (delta impact). Tests for the function are also added.

PR Author Checklist

• [x] Read the Contribution Guide
• [x] Correct target branch selected (if unsure, select develop)
• [x] Descriptive pull request title added
• [x] Source branch up-to-date with target branch
• [x] Documentation updated
• [x] Tests updated
• [x] Tests passing
• [x] No new linter issues
• [x] Changelog updated

PR Reviewer Checklist

• [ ] Read the Contribution Guide
• [ ] CLIMADA Reviewer Checklist passed
• [ ] Tests passing
• [ ] No new linter issues

[chahank]

Can you please merge the develop branch into this branch? All tests are now failing, but I think it is due to a bug that is fixed on develop.

[chahank]

I have one larger general question: from the naming, and what the docstring says, I would expect the new module to compute the absolute differences. However, the current code seems to compute relative differences. What is the rational here? This should maybe be an option?

After these points are resolved, someone should still do a careful check of the actual methods. I briefly went over them, and it seems all fine. But details can be important, in particular also because the test is quite minimal.

[simonameiler]

Can you please merge the develop branch into this branch? All tests are now failing, but I think it is due to a bug that is fixed on develop.

I did. I don't think the bug is fixed on develop yet.

[simonameiler]

I have one larger general question: from the naming, and what the docstring says, I would expect the new module to compute the absolute differences. However, the current code seems to compute relative differences. What is the rational here? This should maybe be an option?

After these points are resolved, someone should still do a careful check of the actual methods. I briefly went over them, and it seems all fine. But details can be important, in particular also because the test is quite minimal.

I resolved all points to my best knowledge. I don't think there should be an option to calculate delta impacts for absolute values. Absolute delta impact calculations are not useful without knowledge of a reference state. I added a few lines in the docstrings reasoning for the relative delta impact calculation.

[simonameiler]

This looks good and useful! There's not much left to do:

• Please resolve all linter issues (except too-many-arguments and too-many-local-variables). This should be rather simple
• The module documentation is missing. Please add an appropriate section to doc/climada/climada.engine.unsequa.rst and double-check the rendered docs.
• The tutorial section on the new class should probably start with an explanation what the class does (current paragraphs 2 and 3), and then mention that it works analogously to the other class (paragraph 1)
• The table of contents in the tutorial was not updated, and the links don't work anyway. Maybe just remove it for now?

I addressed all your points. In my eyes, it's good to go.