Add gallery example to show usage of dcw parameter in Figure.coast

[michaelgrund]

Description of proposed changes

This PR adds a gallery example to show the basic usage of the dcw parameter.

Preview: https://pygmt-dev--2428.org.readthedocs.build/en/2428/gallery/maps/country_polygons.html

Reminders

• Run make format and make check to make sure the code follows the style guide.
• Add tests for new features or tests that would have caught the bug that you're fixing.
• Add new public functions/methods/classes to doc/api/index.rst.
• Write detailed docstrings for all functions/methods.
• If wrapping a new module, open a 'Wrap new GMT module' issue and submit reasonably-sized PRs.
• If adding new functionality, add an example to docstrings or tutorials.
• Use underscores (not hyphens) in names of Python files and directories.

Slash Commands

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• /format: automatically format and lint the code
• /test-gmt-dev: run full tests on the latest GMT development version

[michaelgrund]

/format

[willschlitzer]

I know it's not marked ready for review, but here are some changes I thought would be good.

[willschlitzer]

@michaelgrund Is this ready for review, or are you still working on it?

[michaelgrund]

@michaelgrund Is this ready for review, or are you still working on it?

Yes it is, thanks for your comments and improvements @willschlitzer.

[michaelgrund]

/format

[seisman]

For unknown reasons, all the inline comments disappear in the built page (https://pygmt-dev--2428.org.readthedocs.build/en/2428/gallery/maps/country_polygons.html).

[michaelgrund]

For unknown reasons, all the inline comments disappear in the built page (https://pygmt-dev--2428.org.readthedocs.build/en/2428/gallery/maps/country_polygons.html).

Strange, also the title changes are not considered.

[yvonnefroehlich]

For unknown reasons, all the inline comments disappear in the built page (https://pygmt-dev--2428.org.readthedocs.build/en/2428/gallery/maps/country_polygons.html).

Strange, also the title changes are not considered.

Hm. Did someone change something to fix this? If not, that's really strange, because I face none of these issues. As title of this gallery example I see "Highlight country and continent polygons" (not "Highlight country polygons") and the inline examples are displayed in the API references.

[michaelgrund]

For unknown reasons, all the inline comments disappear in the built page (https://pygmt-dev--2428.org.readthedocs.build/en/2428/gallery/maps/country_polygons.html).

Strange, also the title changes are not considered.

Hm. Did someone change something to fix this? If not, that's really strange, because I face none of these issues. As title of this gallery example I see "Highlight country and continent polygons" (not "Highlight country polygons") and the inline examples are displayed in the API references.

In my case it depends on the device. On my smartphone everything looks fine, when using my laptop the title and comments are not included... after a click on refresh in my browser now it looks also fine on my laptop.

[seisman]

For unknown reasons, all the inline comments disappear in the built page (https://pygmt-dev--2428.org.readthedocs.build/en/2428/gallery/maps/country_polygons.html).

Strange, also the title changes are not considered.

Hm. Did someone change something to fix this? If not, that's really strange, because I face none of these issues. As title of this gallery example I see "Highlight country and continent polygons" (not "Highlight country polygons") and the inline examples are displayed in the API references.

In my case it depends on the device. On my smartphone everything looks fine, when using my laptop the title and comments are not included... after a click on refresh in my browser now it looks also fine on my laptop.

Yes, now it looks good.

[michaelgrund]

Maybe we can add another section for showing how to highlight states/territories of a country (if available), something like:

import pygmt

fig = pygmt.Figure()
fig.coast(
    region=[-130, -70, 24, 52],
    projection="L-100/35/33/45/12c",
    land="gray",
    shorelines="1/0.5p",
    borders=["1/0.8p,black", "2/0.2p,black"],
    frame=True,
    dcw=[
        # Texas with orange fill
        "US.TX+gorange",
        # Kentucky with blue outline
        "US.KY+p1p,blue",
    ],
)

fig.show()

Added this use-case.

[michaelgrund]

/format

[weiji14]

Just one suggestion on the projection for Europe, otherwise ready for final review!