Figure.meca: Refactor the tests for pass a single focal mechanism to spec

[seisman]

Description of proposed changes

The Figure.meca tests are a little messy and difficult to maintain because each test uses different focal mechanisms and event information. I plan to refactor the tests and this PR is the first step.

This PR focuses on testing passing a single focal mechanism to the spec parameter using different data types (dict, file, 1darray and DataFrame). Note that all tests now single a single baseline image test_meca_spec_dict.png.

Changes in this PR:

• Rename the test test_meca_spec_dictionary to test_meca_spec_dict
• Improve the test_meca_spec_dict test with a better baseline image
• Rewrite test_meca_spec_1d_array test to use the existing baseline image
• Rewrite the test_meca_spec_file test to reuse the existing baseline image
• Rename the test test_meca_spec_dataframe to test_meca_spec_two_dataframe
• Add a new test test_meca_spec_dataframe to test passing a dataframe to meca

[github-actions]

Summary of changed images

This is an auto-generated report of images that have changed on the DVC remote

Status	Path
added	pygmt/tests/baseline/test_meca_spec_dict.png
deleted	pygmt/tests/baseline/test_meca_spec_1d_array.png
deleted	pygmt/tests/baseline/test_meca_spec_dictionary.png
deleted	pygmt/tests/baseline/test_meca_spec_file.png
renamed	pygmt/tests/baseline/test_meca_spec_dataframe.png -> pygmt/tests/baseline/test_meca_spec_two_dataframe.png

Image diff(s)

Added images

• pygmt/tests/baseline/test_meca_spec_dict.png

Modified images

Path	Old	New

Report last updated at commit 61c4f2a

[willschlitzer]

Why is this being renamed? As far as I can tell there is just a single DataFrame in this function.

[seisman]

I was planning to have two groups of tests:

1. In tests test_meca_spec_*, a single focal mechanism in different data types (dict, DataFrame, 1darray and plaintext file) is passed to the spec parameter
2. In tests test_meca_spec_two_*, two focal mechanisms in different data types (dict with list as keys, DataFrame, 2D list, 2D array and plaintext file) are passed to the spec parameter.

That's why I added the _two suffix to the tests, but I agree that's not a good name for these tests. Do you have better ideas?

[willschlitzer]

That makes sense. I think it will be hard to come up with a descriptive test name without making it too wordy. I think it might just be easier to update the docstring (I made my suggestion below) to make it clear that it's passing two focal mechanisms.

[willschlitzer]

Suggested change

	Test supplying a pandas.DataFrame containing focal mechanisms and locations
	to the spec parameter.
	Test supplying two focal mechanisms and their locations by passing a pandas.DataFrame
	to the spec parameter.

I think this makes it more clear why "two" is in the function name.

[seisman]

I'm closing the issue and will open another PR to reorganize the meca tests later.