Merge branch 'feature/v0.4.3' into develop

colour/appearance/hellwig2022.py

@@ -854,7 +854,7 @@ def colourfulness_correlate(
     a = as_float_array(a)
     b = as_float_array(b)
 
-    M = 43.0 * N_c * e_t * np.sqrt(a**2 + b**2)
+    M = 43.0 * N_c * e_t * np.hypot(a, b)
 
     return M
 

colour/appearance/kim2009.py

@@ -352,7 +352,7 @@ def XYZ_to_Kim2009(
 
     # Computing the correlate of *chroma* :math:`C`.
     a_k, n_k = 456.5, 0.62
-    C = a_k * spow(np.sqrt(a**2 + b**2), n_k)
+    C = a_k * spow(np.hypot(a, b), n_k)
 
     # Computing the correlate of *colourfulness* :math:`M`.
     a_m, b_m = 0.11, 0.61

colour/contrast/barten1999.py

@@ -189,7 +189,7 @@ def sigma_Barten1999(
     C_ab = as_float_array(C_ab)
     d = as_float_array(d)
 
-    return as_float(np.sqrt(sigma_0**2 + (C_ab * d) ** 2))
+    return as_float(np.hypot(sigma_0, C_ab * d))
 
 
 def retinal_illuminance_Barten1999(

colour/models/din99.py

@@ -243,7 +243,7 @@ def DIN99_to_Lab(
 
     h_99 = np.arctan2(b_99, a_99) - np.radians(c_7)
 
-    C_99 = np.sqrt(a_99**2 + b_99**2)
+    C_99 = np.hypot(a_99, b_99)
     G = np.expm1((c_8 / c_5) * C_99 * k_CH * k_E) / c_6
 
     e = G * np.cos(h_99)

colour/models/rgb/hanbury2003.py

@@ -98,7 +98,7 @@ def RGB_to_IHLS(RGB: ArrayLike) -> NDArrayFloat:
 
     Y, C_1, C_2 = tsplit(vector_dot(MATRIX_RGB_TO_YC_1_C_2, RGB))
 
-    C = np.sqrt(C_1**2 + C_2**2)
+    C = np.hypot(C_1, C_2)
 
     with sdiv_mode():
         C_1_C = sdiv(C_1, C)

colour/plotting/temperature.py

@@ -36,9 +36,10 @@
     UCS_uv_to_xy,
     XYZ_to_UCS,
     xy_to_Luv_uv,
+    xy_to_UCS_uv,
     xy_to_XYZ,
 )
-from colour.temperature import mired_to_CCT, CCT_to_uv
+from colour.temperature import mired_to_CCT, CCT_to_uv, CCT_to_xy_CIE_D
 from colour.plotting import (
     CONSTANTS_COLOUR_STYLE,
     CONSTANTS_ARROW_STYLE,
@@ -70,13 +71,148 @@
 __status__ = "Production"
 
 __all__ = [
+    "plot_daylight_locus",
     "plot_planckian_locus",
     "plot_planckian_locus_in_chromaticity_diagram",
     "plot_planckian_locus_in_chromaticity_diagram_CIE1931",
     "plot_planckian_locus_in_chromaticity_diagram_CIE1960UCS",
 ]
 
 
+@override_style()
+def plot_daylight_locus(
+    daylight_locus_colours: ArrayLike | str | None = None,
+    daylight_locus_opacity: float = 1,
+    daylight_locus_use_mireds: bool = False,
+    method: Literal["CIE 1931", "CIE 1960 UCS", "CIE 1976 UCS"]
+    | str = "CIE 1931",
+    **kwargs: Any,
+) -> Tuple[plt.Figure, plt.Axes]:
+    """
+    Plot the *Daylight Locus* according to given method.
+
+    Parameters
+    ----------
+    daylight_locus_colours
+        Colours of the *Daylight Locus*, if ``daylight_locus_colours`` is set
+        to *RGB*, the colours will be computed according to the corresponding
+        chromaticity coordinates.
+    daylight_locus_opacity
+       Opacity of the *Daylight Locus*.
+    daylight_locus_use_mireds
+        Whether to use micro reciprocal degrees for the iso-temperature lines.
+    method
+        *Chromaticity Diagram* method.
+
+    Other Parameters
+    ----------------
+    kwargs
+        {:func:`colour.plotting.artist`, :func:`colour.plotting.render`},
+        See the documentation of the previously listed definitions.
+
+    Returns
+    -------
+    :class:`tuple`
+        Current figure and axes.
+
+    Examples
+    --------
+    >>> plot_daylight_locus(
+    ...     daylight_locus_colours="RGB",
+    ...     method="CIE 1960 UCS",
+    ... )
+    ... # doctest: +ELLIPSIS
+    (<Figure size ... with 1 Axes>, <...Axes...>)
+
+    .. image:: ../_static/Plotting_Plot_Daylight_Locus.png
+        :align: center
+        :alt: plot_daylight_locus
+    """
+
+    method = validate_method(
+        method, ["CIE 1931", "CIE 1960 UCS", "CIE 1976 UCS"]
+    )
+
+    daylight_locus_colours = optional(
+        daylight_locus_colours, CONSTANTS_COLOUR_STYLE.colour.dark
+    )
+
+    settings: Dict[str, Any] = {"uniform": True}
+    settings.update(kwargs)
+
+    _figure, axes = artist(**settings)
+
+    if method == "cie 1931":
+
+        def xy_to_ij(xy: NDArrayFloat) -> NDArrayFloat:
+            """
+            Convert given *CIE xy* chromaticity coordinates to *ij*
+            chromaticity coordinates.
+            """
+
+            return xy
+
+    elif method == "cie 1960 ucs":
+
+        def xy_to_ij(xy: NDArrayFloat) -> NDArrayFloat:
+            """
+            Convert given *CIE xy* chromaticity coordinates to *ij*
+            chromaticity coordinates.
+            """
+
+            return xy_to_UCS_uv(xy)
+
+    elif method == "cie 1976 ucs":
+
+        def xy_to_ij(xy: NDArrayFloat) -> NDArrayFloat:
+            """
+            Convert given *CIE xy* chromaticity coordinates to *ij*
+            chromaticity coordinates.
+            """
+
+            return xy_to_Luv_uv(xy)
+
+    def CCT_to_plotting_colourspace(CCT):
+        """
+        Convert given correlated colour temperature :math:`T_{cp}` to the
+        default plotting colourspace.
+        """
+
+        return normalise_maximum(
+            XYZ_to_plotting_colourspace(xy_to_XYZ(CCT_to_xy_CIE_D(CCT))),
+            axis=-1,
+        )
+
+    start, end = (
+        (0, 1000) if daylight_locus_use_mireds else (1e6 / 600, 1e6 / 10)
+    )
+
+    CCT = np.arange(start, end + 100, 10) * 1.4388 / 1.4380
+    CCT = mired_to_CCT(CCT) if daylight_locus_use_mireds else CCT
+    ij = xy_to_ij(CCT_to_xy_CIE_D(CCT)).reshape(-1, 1, 2)
+
+    use_RGB_daylight_locus_colours = (
+        str(daylight_locus_colours).upper() == "RGB"
+    )
+    if use_RGB_daylight_locus_colours:
+        pl_colours = CCT_to_plotting_colourspace(CCT)
+    else:
+        pl_colours = daylight_locus_colours
+
+    line_collection = LineCollection(
+        np.concatenate([ij[:-1], ij[1:]], axis=1),
+        colors=pl_colours,
+        alpha=daylight_locus_opacity,
+        zorder=CONSTANTS_COLOUR_STYLE.zorder.foreground_line,
+    )
+    axes.add_collection(line_collection)
+
+    settings = {"axes": axes}
+    settings.update(kwargs)
+
+    return render(**settings)
+
+
 @override_style()
 def plot_planckian_locus(
     planckian_locus_colours: ArrayLike | str | None = None,
@@ -128,7 +264,6 @@ def plot_planckian_locus(
     >>> plot_planckian_locus(
     ...     planckian_locus_colours="RGB",
     ...     method="CIE 1960 UCS",
-    ...     use_mireds=True,
     ... )
     ... # doctest: +ELLIPSIS
     (<Figure size ... with 1 Axes>, <...Axes...>)
@@ -194,8 +329,8 @@ def uv_to_ij(uv: NDArrayFloat) -> NDArrayFloat:
 
     def CCT_D_uv_to_plotting_colourspace(CCT_D_uv):
         """
-        Convert given *uv* chromaticity coordinates to the default plotting
-        colourspace.
+        Convert given correlated colour temperature :math:`T_{cp}` and
+        :math:`\\Delta_{uv}` to the default plotting colourspace.
         """
 
         return normalise_maximum(

colour/plotting/tests/test_temperature.py

@@ -9,6 +9,7 @@
     plot_planckian_locus_in_chromaticity_diagram_CIE1960UCS,
 )
 from colour.plotting.temperature import (
+    plot_daylight_locus,
     plot_planckian_locus,
     plot_planckian_locus_in_chromaticity_diagram,
 )
@@ -21,13 +22,46 @@
 __status__ = "Production"
 
 __all__ = [
+    "TestPlotDaylightLocus",
     "TestPlotPlanckianLocus",
     "TestPlotPlanckianLocusInChromaticityDiagram",
     "TestPlotPlanckianLocusInChromaticityDiagramCIE1931",
     "TestPlotPlanckianLocusInChromaticityDiagramCIE1960UCS",
 ]
 
 
+class TestPlotDaylightLocus(unittest.TestCase):
+    """
+    Define :func:`colour.plotting.temperature.plot_daylight_locus` definition
+    unit tests methods.
+    """
+
+    def test_plot_daylight_locus(self):
+        """
+        Test :func:`colour.plotting.temperature.plot_daylight_locus`
+        definition.
+        """
+
+        figure, axes = plot_daylight_locus()
+
+        self.assertIsInstance(figure, Figure)
+        self.assertIsInstance(axes, Axes)
+
+        self.assertRaises(
+            ValueError, lambda: plot_daylight_locus(method="Undefined")
+        )
+
+        figure, axes = plot_daylight_locus(method="CIE 1976 UCS")
+
+        self.assertIsInstance(figure, Figure)
+        self.assertIsInstance(axes, Axes)
+
+        figure, axes = plot_daylight_locus(planckian_locus_colours="RGB")
+
+        self.assertIsInstance(figure, Figure)
+        self.assertIsInstance(axes, Axes)
+
+
 class TestPlotPlanckianLocus(unittest.TestCase):
     """
     Define :func:`colour.plotting.temperature.plot_planckian_locus` definition

docs/colour.plotting.rst

@@ -272,6 +272,7 @@ Colour Temperature & Correlated Colour Temperature
 .. autosummary::
     :toctree: generated/
 
+    plot_daylight_locus
     plot_planckian_locus
     plot_planckian_locus_in_chromaticity_diagram
 

utilities/generate_plots.py

@@ -117,6 +117,7 @@
     plot_hull_section_contour,
 )
 from colour.plotting.temperature import (  # noqa: E402
+    plot_daylight_locus,
     plot_planckian_locus,
     plot_planckian_locus_in_chromaticity_diagram,
 )
@@ -909,6 +910,13 @@ def generate_documentation_plots(output_directory: str):
         )[0]
     )
 
+    arguments["filename"] = os.path.join(
+        output_directory, "Plotting_Plot_Daylight_Locus.png"
+    )
+    plt.close(
+        plot_daylight_locus(daylight_locus_colours="RGB", **arguments)[0]
+    )
+
     arguments["filename"] = os.path.join(
         output_directory, "Plotting_Plot_Planckian_Locus.png"
     )