Wrap solar (#804)

Co-authored-by: Dongdong Tian <[email protected]>
Co-authored-by: Wei Ji <[email protected]>

doc/api/index.rst

@@ -38,6 +38,7 @@ Plotting data and laying out the map:
     Figure.plot3d
     Figure.set_panel
     Figure.shift_origin
+    Figure.solar
     Figure.subplot
     Figure.text
 

examples/gallery/embellishments/solar.py

@@ -0,0 +1,48 @@
+"""
+Day-night terminator line and twilights
+---------------------------------------
+
+Use :meth:`pygmt.Figure.solar` to show the different transition stages between daytime
+and nightime. The parameter ``terminator`` is used to set the twilight stage, and can be
+either 'day-night' (brightest), 'civil', 'nautical', or 'astronomical' (darkest). Refer
+to https://en.wikipedia.org/wiki/Twilight for more information.
+"""
+import datetime
+
+import pygmt
+
+fig = pygmt.Figure()
+# Create a figure showing the global region on a Mollweide projection
+# Land color is set to dark green and water color is set to light blue
+fig.coast(region="d", projection="W0/15c", land="darkgreen", water="lightblue")
+# Set a time for the day-night terminator and twilights, 1700 UTC on January 1, 2000
+terminator_datetime = datetime.datetime(
+    year=2000, month=1, day=1, hour=17, minute=0, second=0
+)
+# Set the pen line to be 0.5p thick
+# Set the fill for the night area to be navy blue at different transparency levels
+fig.solar(
+    terminator="day_night",
+    terminator_datetime=terminator_datetime,
+    fill="navyblue@95",
+    pen="0.5p",
+)
+fig.solar(
+    terminator="civil",
+    terminator_datetime=terminator_datetime,
+    fill="navyblue@85",
+    pen="0.5p",
+)
+fig.solar(
+    terminator="nautical",
+    terminator_datetime=terminator_datetime,
+    fill="navyblue@80",
+    pen="0.5p",
+)
+fig.solar(
+    terminator="astronomical",
+    terminator_datetime=terminator_datetime,
+    fill="navyblue@80",
+    pen="0.5p",
+)
+fig.show()

pygmt/figure.py

@@ -391,6 +391,7 @@ def _repr_html_(self):
         plot,
         plot3d,
         set_panel,
+        solar,
         subplot,
         text,
     )

pygmt/src/__init__.py

@@ -25,6 +25,7 @@
 from pygmt.src.meca import meca
 from pygmt.src.plot import plot
 from pygmt.src.plot3d import plot3d
+from pygmt.src.solar import solar
 from pygmt.src.subplot import set_panel, subplot
 from pygmt.src.surface import surface
 from pygmt.src.text import text_ as text  # "text" is an argument within "text_"

pygmt/src/solar.py

@@ -0,0 +1,97 @@
+"""
+solar - Plot day-night terminators and twilight.
+"""
+import pandas as pd
+from pygmt.clib import Session
+from pygmt.exceptions import GMTInvalidInput
+from pygmt.helpers import build_arg_string, fmt_docstring, kwargs_to_strings, use_alias
+
+
+@fmt_docstring
+@use_alias(
+    B="frame",
+    G="fill",
+    J="projection",
+    R="region",
+    U="timestamp",
+    V="verbose",
+    W="pen",
+    X="xshift",
+    Y="yshift",
+    c="panel",
+    p="perspective",
+    t="transparency",
+)
+@kwargs_to_strings(R="sequence", c="sequence_comma", p="sequence")
+def solar(self, terminator="d", terminator_datetime=None, **kwargs):
+    r"""
+    Plot day-light terminators or twilights.
+
+    This function plots the day-night terminator. Alternatively, it can plot
+    the terminators for civil twilight, nautical twilight, or astronomical
+    twilight.
+
+    Full parameter list at :gmt-docs:`solar.html`
+
+    {aliases}
+
+    Parameters
+    ----------
+    terminator : str
+        Set the type of terminator displayed. Valid arguments are
+        **day_night**, **civil**, **nautical**, and **astronomical**, which
+        can be set with either the full name or the first letter of the name.
+        [Default is **day_night**]
+
+        Refer to https://en.wikipedia.org/wiki/Twilight for the definitions of
+        different types of twilight.
+    terminator_datetime : str or datetime object
+        Set the UTC date and time of the displayed terminator. It can be
+        passed as a string or Python datetime object.
+        [Default is the current UTC date and time]
+    {R}
+    {J}
+    {B}
+    fill : str
+        Color or pattern for filling of terminators.
+    pen : str
+        Set pen attributes for lines. The default pen
+        is ``default,black,solid``.
+    {U}
+    {V}
+    {XY}
+    {c}
+    {p}
+    {t}
+    """
+
+    kwargs = self._preprocess(**kwargs)  # pylint: disable=protected-access
+    if "T" in kwargs:
+        raise GMTInvalidInput(
+            "Use 'terminator' and 'terminator_datetime' instead of 'T'."
+        )
+    if terminator not in [
+        "day_night",
+        "civil",
+        "nautical",
+        "astronomical",
+        "d",
+        "c",
+        "n",
+        "a",
+    ]:
+        raise GMTInvalidInput(
+            f"Unrecognized solar terminator type '{terminator}'. Valid values "
+            "are 'day_night', 'civil', 'nautical', and 'astronomical'."
+        )
+    kwargs["T"] = terminator[0]
+    if terminator_datetime:
+        try:
+            datetime_string = pd.to_datetime(terminator_datetime).strftime(
+                "%Y-%m-%dT%H:%M:%S.%f"
+            )
+        except ValueError as verr:
+            raise GMTInvalidInput("Unrecognized datetime format.") from verr
+        kwargs["T"] += f"+d{datetime_string}"
+    with Session() as lib:
+        lib.call_module("solar", build_arg_string(kwargs))

pygmt/tests/baseline/test_solar_set_terminator_datetime.png.dvc

@@ -0,0 +1,4 @@
+outs:
+- md5: 0a7f4959b500b6fa3a560a6368db0f90
+  size: 25982
+  path: test_solar_set_terminator_datetime.png

pygmt/tests/baseline/test_solar_terminators.png.dvc

@@ -0,0 +1,4 @@
+outs:
+- md5: 54c92bea64e0fc76c62601cb6131f22e
+  size: 44160
+  path: test_solar_terminators.png

pygmt/tests/test_solar.py

@@ -0,0 +1,120 @@
+"""
+Tests for solar.
+"""
+import datetime
+
+import pytest
+from pygmt import Figure
+from pygmt.exceptions import GMTInvalidInput
+
+
+@pytest.mark.mpl_image_compare
+def test_solar_terminators():
+    """
+    Test passing the solar argument with a time string and no terminator type
+    to confirm the default terminator type.
+    """
+    fig = Figure()
+    fig.basemap(region="d", projection="W0/15c", frame="a")
+    fig.solar(
+        terminator="d",
+        pen="1p,blue",
+        terminator_datetime="1990-02-17 04:25:00",
+    )
+    fig.solar(
+        terminator="a",
+        pen="1p,red",
+        terminator_datetime="1990-02-17 04:25:00",
+    )
+    fig.solar(
+        terminator="c",
+        pen="1p,green",
+        terminator_datetime="1990-02-17 04:25:00",
+    )
+    fig.solar(
+        terminator="n",
+        pen="1p,yellow",
+        terminator_datetime="1990-02-17 04:25:00",
+    )
+    return fig
+
+
+@pytest.mark.mpl_image_compare(filename="test_solar_set_terminator_datetime.png")
+@pytest.mark.parametrize(
+    "terminator_datetime",
+    [
+        pytest.param("1990-02-17 04:25:00", id="terminator_datetime_string"),
+        datetime.datetime(year=1990, month=2, day=17, hour=4, minute=25, second=0),
+    ],
+)
+def test_solar_set_terminator_datetime(terminator_datetime):
+    """
+    Test passing the solar argument with the day_night terminator and a
+    datetime string.
+    """
+    fig = Figure()
+    fig.solar(
+        region="d",
+        projection="W0/15c",
+        frame="a",
+        terminator="day_night",
+        terminator_datetime=terminator_datetime,
+    )
+    return fig
+
+
+def test_invalid_terminator_type():
+    """
+    Test if solar fails when it receives an invalid terminator type.
+    """
+    fig = Figure()
+    with pytest.raises(GMTInvalidInput):
+        fig.solar(
+            region="d",
+            projection="W0/15c",
+            frame="a",
+            terminator="invalid",
+        )
+
+
+def test_invalid_parameter():
+    """
+    Test if solar fails when it receives a GMT argument for 'T' instead of the
+    PyGMT arguments for 'terminator' and 'terminator_datetime'.
+    """
+    fig = Figure()
+    with pytest.raises(GMTInvalidInput):
+        # Use single-letter option 'T' for testing
+        fig.solar(
+            region="d", projection="W0/15c", frame="a", T="d+d1990-02-17T04:25:00"
+        )
+
+
+def test_invalid_datetime():
+    """
+    Test if solar fails when it receives an invalid datetime string.
+    """
+    fig = Figure()
+    with pytest.raises(GMTInvalidInput):
+        fig.solar(
+            region="d",
+            projection="W0/15c",
+            frame="a",
+            terminator_datetime="199A-02-17 04:25:00",
+        )
+
+
+@pytest.mark.mpl_image_compare(filename="test_solar_set_terminator_datetime.png")
+def test_solar_default_terminator():
+    """
+    Test passing the solar argument with a time string and no terminator type
+    to confirm the default terminator type.
+    """
+    fig = Figure()
+    fig.solar(
+        region="d",
+        projection="W0/15c",
+        frame="a",
+        terminator_datetime="1990-02-17 04:25:00",
+    )
+    return fig