From 7b7a06b404c22b7e62bfd816089e8e8fb6f7f303 Mon Sep 17 00:00:00 2001
From: nbarlowATI <nbarlow@turing.ac.uk>
Date: Fri, 20 Oct 2023 16:45:17 +0100
Subject: [PATCH 1/3] First attempt for individual hatching styles for
 stackplot

---
 lib/matplotlib/stackplot.py | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/lib/matplotlib/stackplot.py b/lib/matplotlib/stackplot.py
index 2629593683e5..a88ee5b61d4b 100644
--- a/lib/matplotlib/stackplot.py
+++ b/lib/matplotlib/stackplot.py
@@ -6,6 +6,7 @@
 (https://stackoverflow.com/users/66549/doug)
 """
 
+from collections.abc import Iterable
 import itertools
 
 import numpy as np
@@ -16,7 +17,7 @@
 
 
 def stackplot(axes, x, *args,
-              labels=(), colors=None, baseline='zero',
+              labels=(), colors=None, hatch=None, baseline='zero',
               **kwargs):
     """
     Draw a stacked area plot.
@@ -55,6 +56,12 @@ def stackplot(axes, x, *args,
 
         If not specified, the colors from the Axes property cycle will be used.
 
+    hatch : list of hatching styles, optional
+        A sequence of styles to be cycled through for filling the stacked areas.
+        The sequence need not be exactly the same length as the number
+        of provided *y*, in which case the styles will repeat from the
+        beginning.
+
     data : indexable object, optional
         DATA_PARAMETER_PLACEHOLDER
 
@@ -76,6 +83,14 @@ def stackplot(axes, x, *args,
     else:
         colors = (axes._get_lines.get_next_color() for _ in y)
 
+    if hatch:
+        if isinstance(hatch, Iterable):
+            hatch = itertools.cycle(hatch)
+        else:
+            hatch = (hatch for _ in y)
+    else:
+        hatch = (" " for _ in y)
+
     # Assume data passed has not been 'stacked', so stack it here.
     # We'll need a float buffer for the upcoming calculations.
     stack = np.cumsum(y, axis=0, dtype=np.promote_types(y.dtype, np.float32))
@@ -113,7 +128,7 @@ def stackplot(axes, x, *args,
 
     # Color between x = 0 and the first array.
     coll = axes.fill_between(x, first_line, stack[0, :],
-                             facecolor=next(colors), label=next(labels, None),
+                             facecolor=next(colors), hatch=next(hatch), label=next(labels, None),
                              **kwargs)
     coll.sticky_edges.y[:] = [0]
     r = [coll]
@@ -122,6 +137,7 @@ def stackplot(axes, x, *args,
     for i in range(len(y) - 1):
         r.append(axes.fill_between(x, stack[i, :], stack[i + 1, :],
                                    facecolor=next(colors),
+                                   hatch=next(hatch),
                                    label=next(labels, None),
                                    **kwargs))
     return r

From 11591b6b17aa2a751d058b089c95f6ceaddf87f7 Mon Sep 17 00:00:00 2001
From: nbarlowATI <nbarlow@turing.ac.uk>
Date: Fri, 20 Oct 2023 17:07:43 +0100
Subject: [PATCH 2/3] break up overlong line

---
 lib/matplotlib/stackplot.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/matplotlib/stackplot.py b/lib/matplotlib/stackplot.py
index a88ee5b61d4b..f92a0973cb18 100644
--- a/lib/matplotlib/stackplot.py
+++ b/lib/matplotlib/stackplot.py
@@ -128,7 +128,9 @@ def stackplot(axes, x, *args,
 
     # Color between x = 0 and the first array.
     coll = axes.fill_between(x, first_line, stack[0, :],
-                             facecolor=next(colors), hatch=next(hatch), label=next(labels, None),
+                             facecolor=next(colors),
+                             hatch=next(hatch),
+                             label=next(labels, None),
                              **kwargs)
     coll.sticky_edges.y[:] = [0]
     r = [coll]

From 8773619d6798d6dae1ac4d76017e52d86d90a828 Mon Sep 17 00:00:00 2001
From: nbarlowATI <nbarlow@turing.ac.uk>
Date: Sun, 22 Oct 2023 12:17:55 +0100
Subject: [PATCH 3/3] hatching in stackplot with strings or None for hatch
 argument

---
 lib/matplotlib/stackplot.py | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/lib/matplotlib/stackplot.py b/lib/matplotlib/stackplot.py
index f92a0973cb18..8b16b2f2e4e3 100644
--- a/lib/matplotlib/stackplot.py
+++ b/lib/matplotlib/stackplot.py
@@ -6,7 +6,6 @@
 (https://stackoverflow.com/users/66549/doug)
 """
 
-from collections.abc import Iterable
 import itertools
 
 import numpy as np
@@ -83,13 +82,10 @@ def stackplot(axes, x, *args,
     else:
         colors = (axes._get_lines.get_next_color() for _ in y)
 
-    if hatch:
-        if isinstance(hatch, Iterable):
-            hatch = itertools.cycle(hatch)
-        else:
-            hatch = (hatch for _ in y)
+    if not hatch or isinstance(hatch, str):
+        hatch = itertools.cycle([hatch])
     else:
-        hatch = (" " for _ in y)
+        hatch = itertools.cycle(hatch)
 
     # Assume data passed has not been 'stacked', so stack it here.
     # We'll need a float buffer for the upcoming calculations.