Merge pull request #17767 from dstansby/bar-hatch

tacaswell · web-flow · commit 8d2c16b23c91 · 2020-06-28T13:53:36.000-04:00
ENH: Allow list of hatches to {bar, barh}
diff --git a/doc/users/next_whats_new/bar_hatches.rst b/doc/users/next_whats_new/bar_hatches.rst
@@ -0,0 +1,14 @@
+A list of hatches can be specified to `~.axes.Axes.bar` and `~.axes.Axes.barh`
+------------------------------------------------------------------------------
+
+Similar to some other rectangle properties, it is now possible to hand a list
+of hatch styles to `~.axes.Axes.bar` and `~.axes.Axes.barh` in order to create
+bars with different hatch styles, e.g.
+
+.. plot::
+
+  import matplotlib.pyplot as plt
+
+  fig, ax = plt.subplots()
+  ax.bar([1, 2], [2, 3], hatch=['+', 'o'])
+  plt.show()
diff --git a/examples/shapes_and_collections/hatch_demo.py b/examples/shapes_and_collections/hatch_demo.py
@@ -6,25 +6,24 @@
 Hatching (pattern filled polygons) is supported currently in the PS,
 PDF, SVG and Agg backends only.
 """
+import numpy as np
 import matplotlib.pyplot as plt
 from matplotlib.patches import Ellipse, Polygon
 
+x = np.arange(1, 5)
+y1 = np.arange(1, 5)
+y2 = np.ones(y1.shape) * 4
+
 fig, (ax1, ax2, ax3) = plt.subplots(3)
 
-ax1.bar(range(1, 5), range(1, 5), color='red', edgecolor='black', hatch="/")
-ax1.bar(range(1, 5), [6] * 4, bottom=range(1, 5),
-        color='blue', edgecolor='black', hatch='//')
+ax1.bar(x, y1, edgecolor='black', hatch="/")
+ax1.bar(x, y2, bottom=y1, edgecolor='black', hatch='//')
 ax1.set_xticks([1.5, 2.5, 3.5, 4.5])
 
-bars = ax2.bar(range(1, 5), range(1, 5), color='yellow', ecolor='black') + \
-    ax2.bar(range(1, 5), [6] * 4, bottom=range(1, 5),
-            color='green', ecolor='black')
+ax2.bar(x, y1, edgecolor='black', hatch=['-', '+', 'x', '\\'])
+ax2.bar(x, y2, bottom=y1, edgecolor='black', hatch=['*', 'o', 'O', '.'])
 ax2.set_xticks([1.5, 2.5, 3.5, 4.5])
 
-patterns = ('-', '+', 'x', '\\', '*', 'o', 'O', '.')
-for bar, pattern in zip(bars, patterns):
-    bar.set_hatch(pattern)
-
 ax3.fill([1, 3, 3, 1], [1, 1, 2, 2], fill=False, hatch='\\')
 ax3.add_patch(Ellipse((4, 1.5), 4, 0.5, fill=False, hatch='*'))
 ax3.add_patch(Polygon([[0, 0], [4, 1.1], [6, 2.5], [2, 1.4]], closed=True,
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -2366,6 +2366,7 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
             color = self._get_patches_for_fill.get_next_color()
         edgecolor = kwargs.pop('edgecolor', None)
         linewidth = kwargs.pop('linewidth', None)
+        hatch = kwargs.pop('hatch', None)
 
         # Because xerr and yerr will be passed to errorbar, most dimension
         # checking and processing will be left to the errorbar method.
@@ -2427,9 +2428,9 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
             if yerr is not None:
                 yerr = self._convert_dx(yerr, y0, y, self.convert_yunits)
 
-        x, height, width, y, linewidth = np.broadcast_arrays(
+        x, height, width, y, linewidth, hatch = np.broadcast_arrays(
             # Make args iterable too.
-            np.atleast_1d(x), height, width, y, linewidth)
+            np.atleast_1d(x), height, width, y, linewidth, hatch)
 
         # Now that units have been converted, set the tick locations.
         if orientation == 'vertical':
@@ -2440,6 +2441,7 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
             tick_label_position = y
 
         linewidth = itertools.cycle(np.atleast_1d(linewidth))
+        hatch = itertools.cycle(np.atleast_1d(hatch))
         color = itertools.chain(itertools.cycle(mcolors.to_rgba_array(color)),
                                 # Fallback if color == "none".
                                 itertools.repeat('none'))
@@ -2476,14 +2478,16 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
             bottom = y
 
         patches = []
-        args = zip(left, bottom, width, height, color, edgecolor, linewidth)
-        for l, b, w, h, c, e, lw in args:
+        args = zip(left, bottom, width, height, color, edgecolor, linewidth,
+                   hatch)
+        for l, b, w, h, c, e, lw, htch in args:
             r = mpatches.Rectangle(
                 xy=(l, b), width=w, height=h,
                 facecolor=c,
                 edgecolor=e,
                 linewidth=lw,
                 label='_nolegend_',
+                hatch=htch,
                 )
             r.update(kwargs)
             r.get_path()._interpolation_steps = 100
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -1551,6 +1551,21 @@ def test_bar_pandas_indexed(pd):
     ax.bar(df.x, 1., width=df.width)
 
 
+@check_figures_equal()
+@pytest.mark.style('default')
+def test_bar_hatches(fig_test, fig_ref):
+    ax_test = fig_test.subplots()
+    ax_ref = fig_ref.subplots()
+
+    x = [1, 2]
+    y = [2, 3]
+    hatches = ['x', 'o']
+    for i in range(2):
+        ax_ref.bar(x[i], y[i], color='C0', hatch=hatches[i])
+
+    ax_test.bar(x, y, hatch=hatches)
+
+
 def test_pandas_minimal_plot(pd):
     # smoke test that series and index objcets do not warn
     x = pd.Series([1, 2], dtype="float64")
