plot histogram with class bins

.github/workflows/testing.yml

@@ -76,7 +76,8 @@ jobs:
           -n auto \
           --color yes \
           --cov mapclassify --cov-report xml --cov-append \
-          --doctest-only mapclassify
+          --doctest-only \
+          --mpl mapclassify
 
       - name: codecov (${{ matrix.os }}, ${{ matrix.environment-file }})
         uses: codecov/codecov-action@v4

ci/310-numba.yaml

@@ -15,6 +15,7 @@ dependencies:
   - pytest
   - pytest-cov
   - pytest-xdist
+  - pytest-mpl
   - codecov
   - matplotlib
   # optional

ci/310.yaml

@@ -15,5 +15,6 @@ dependencies:
   - pytest
   - pytest-cov
   - pytest-xdist
+  - pytest-mpl
   - codecov
   - matplotlib

ci/311-numba.yaml

@@ -15,6 +15,7 @@ dependencies:
   - pytest
   - pytest-cov
   - pytest-xdist
+  - pytest-mpl
   - codecov
   - matplotlib
   # optional

ci/311.yaml

@@ -15,6 +15,7 @@ dependencies:
   - pytest
   - pytest-cov
   - pytest-xdist
+  - pytest-mpl
   - codecov
   - matplotlib
   # docs

ci/312-dev.yaml

@@ -7,6 +7,7 @@ dependencies:
   - pytest
   - pytest-cov
   - pytest-xdist
+  - pytest-mpl
   - codecov
   # optional
   - pyproj

ci/312-numba.yaml

@@ -16,6 +16,7 @@ dependencies:
   - pytest-cov
   - pytest-xdist
   - pytest-doctestplus
+  - pytest-mpl
   - codecov
   - matplotlib
   # optional

ci/312.yaml

@@ -15,6 +15,7 @@ dependencies:
   - pytest
   - pytest-cov
   - pytest-xdist
+  - pytest-mpl
   - codecov
   - matplotlib
   # docs

mapclassify/classifiers.py

@@ -1123,6 +1123,66 @@ def plot(
             plt.savefig(file_name, dpi=dpi)
         return f, ax
 
+    def plot_histogram(
+        self,
+        color="dodgerblue",
+        linecolor="black",
+        linewidth=None,
+        ax=None,
+        despine=True,
+        **kwargs,
+    ):
+        """Plot histogram of `y` with bin values superimposed
+
+        Parameters
+        ----------
+        color : str, optional
+            hue to color bars of the histogram, by default "dodgerblue".
+        linecolor : str, optional
+            color of the lines demarcating each class bin, by default "black"
+        linewidth : int, optional
+            change the linewidth demarcating each class bin
+        ax : matplotlib.Axes, optional
+            axes object to plot onto, by default None
+        despine : bool, optional
+            If True, to use seaborn's despine function to remove top and right axes,
+            default is True
+        kwargs : dict, optional
+            additional keyword arguments passed to matplotlib.axes.Axes.hist, by default
+            None
+
+        Returns
+        -------
+        matplotlib.Axes
+            an Axes object with histogram and class bins
+
+        Raises
+        ------
+        ImportError
+            depends matplotlib and rasies if not installed
+        """
+        try:
+            import matplotlib.pyplot as plt
+
+            if ax is None:
+                _, ax = plt.subplots()
+        except ImportError as e:
+            raise ImportError from e(
+                "You must have matplotlib available to use this function"
+            )
+        # plot `y` as a histogram
+        ax.hist(self.y, color=color, **kwargs)
+        # get the top of the ax so we know how high to raise each class bar
+        lim = ax.get_ylim()[1]
+        # plot upper limit of each bin
+        for i in self.bins:
+            ax.vlines(i, 0, lim, color=linecolor, linewidth=linewidth)
+        # despine if specified
+        if despine:
+            ax.spines["right"].set_visible(False)
+            ax.spines["top"].set_visible(False)
+        return ax
+
 
 class HeadTailBreaks(MapClassifier):
     """

mapclassify/tests/test_mapclassify.py

@@ -736,3 +736,26 @@ def test_pooled_bad_classifier(self):
         message = f"'{classifier}' not a valid classifier."
         with pytest.raises(ValueError, match=message):
             Pooled(self.data, classifier=classifier, k=4)
+
+
+class TestPlots:
+    def setup_method(self):
+        n = 20
+        self.data = numpy.array([numpy.arange(n) + i * n for i in range(1, 4)]).T
+
+    @pytest.mark.mpl_image_compare
+    def test_histogram_plot(self):
+        ax = Quantiles(self.data).plot_histogram()
+        return ax.get_figure()
+
+    @pytest.mark.mpl_image_compare
+    def test_histogram_plot_despine(self):
+        ax = Quantiles(self.data).plot_histogram(despine=False)
+        return ax.get_figure()
+
+    @pytest.mark.mpl_image_compare
+    def test_histogram_plot_linewidth(self):
+        ax = Quantiles(self.data).plot_histogram(
+            linewidth=3, linecolor="red", color="yellow"
+        )
+        return ax.get_figure()

pyproject.toml

@@ -8,13 +8,13 @@ build-backend = "setuptools.build_meta"
 name = "mapclassify"
 dynamic = ["version"]
 maintainers = [
-    {name = "Serge Rey", email = "sjsrey@gmail.com"},
-    {name = "Wei Kang", email = "weikang9009@gmail.com"},
+    { name = "Serge Rey", email = "sjsrey@gmail.com" },
+    { name = "Wei Kang", email = "weikang9009@gmail.com" },
 ]
-license = {text = "BSD 3-Clause"}
+license = { text = "BSD 3-Clause" }
 description = "Classification Schemes for Choropleth Maps."
 keywords = ["spatial statistics", "geovisualization"]
-readme = {text = """\
+readme = { text = """\
 `mapclassify` implements a family of classification schemes for choropleth maps.
 Its focus is on the determination of the number of classes, and the assignment
 of observations to those classes. It is intended for use with upstream mapping
@@ -26,7 +26,7 @@ For further theoretical background see "`Choropleth Mapping`_" in Rey, S.J., D.
 .. _geopandas: https://geopandas.org/mapping.html
 .. _geoplot: https://residentmario.github.io/geoplot/user_guide/Customizing_Plots.html
 .. _Choropleth Mapping: https://geographicdata.science/book/notebooks/05_choropleth.html
-""", content-type = "text/x-rst"}
+""", content-type = "text/x-rst" }
 classifiers = [
     "Programming Language :: Python :: 3",
     "Programming Language :: Python :: 3.9",
@@ -52,14 +52,8 @@ Home = "https://pysal.org/mapclassify/"
 Repository = "https://github.com/pysal/mapclassify"
 
 [project.optional-dependencies]
-speedups = [
-    "numba>=0.54",
-]
-dev = [
-    "black",
-    "ruff",
-    "pre-commit",
-]
+speedups = ["numba>=0.54"]
+dev = ["black", "ruff", "pre-commit"]
 docs = [
     "nbsphinx",
     "numpydoc",
@@ -76,14 +70,12 @@ tests = [
     "pytest-cov",
     "pytest-xdist",
     "pytest-doctestplus",
+    "pytest-mpl"
 ]
 all = ["numba[speedups,dev,docs,tests]"]
 
 [tool.setuptools.packages.find]
-include = [
-    "mapclassify",
-    "mapclassify.*",
-]
+include = ["mapclassify", "mapclassify.*"]
 
 [tool.black]
 line-length = 88