From f58c83e7162b97945da5a8f1c510542ebad71970 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Wed, 24 Jun 2026 14:06:31 +0200
Subject: [PATCH 01/21] Add example for non-co-registered curves

---
 .../lines/fill_areas_between_curves.py        | 40 ++++++++++++++++++-
 1 file changed, 38 insertions(+), 2 deletions(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index e73d0ba73f4..3093dd4828f 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -3,7 +3,8 @@
 ========================
 The :meth:`pygmt.Figure.fill_between` method fills the area between two curves y1 and
 y2. Different fills (colors or patterns) can be used for the areas y1 > y2 and
-y1 < y2. Optionally, the curves can be drawn.
+y1 < y2. Optionally, the curves can be drawn. The two curves can be co-registered or
+have different x-coordinates.
 To plot an anomaly along a track use :meth:`pygmt.Figure.wiggle` and see the gallery
 example :doc:`Wiggle along tracks </gallery/lines/wiggle>`.
 """
@@ -14,7 +15,7 @@
 
 # Generate some test data
 x = np.arange(-10, 10.2, 0.1)
-y1 = np.sin(x * 3)
+y1 = np.sin(3 * x)
 y2 = np.sin(x / 2)
 
 
@@ -68,4 +69,39 @@
 )
 fig.show()
 
+
+# %%
+# Now, we use two non-co-registered curves, e.g., the two curves have different
+# x-coordinates. For providing the x-coordinates for the second curve, use
+# parameter ``x2``.
+
+x1 = np.linspace(0, 4, 100)
+x2 = np.array(
+    [0, 0.21, 0.4, 0.63, 0.89, 1.18, 1.45, 1.69, 1.96, 2.26, 2.61, 3.23, 3.49, 4.0]
+)
+y1 = 0.5 * np.cos(3 * x1)
+y2 = 0.5 * np.cos(3 * x2)
+
+fig = pygmt.Figure()
+fig.basemap(region=[0, 4, -1.2, 1.2], projection="X10c/5c", frame=True)
+
+fig.fill_between(
+    x=x1,
+    y=y1,
+    x2=x2,
+    y2=y2,
+    fill="orange",
+    fill2="steelblue",
+    pen="1p,darkred",
+    pen2="1p,darkblue",
+    label="y1(x1)",
+    label2="y2(x2)",
+)
+# Mark sampling points
+fig.plot(x=x1, y=y1, style="c0.1c", fill="darkred")
+fig.plot(x=x2, y=y2, style="c0.1c", fill="darkblue")
+
+fig.legend()
+
+
 # sphinx_gallery_thumbnail_number = 1

From 78fa90f3dbae7dea423ac8be5a76b91e021da5c2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Wed, 24 Jun 2026 15:47:38 +0200
Subject: [PATCH 02/21] Add fig.show

---
 examples/gallery/lines/fill_areas_between_curves.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index 3093dd4828f..36d9ab9015d 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -75,11 +75,11 @@
 # x-coordinates. For providing the x-coordinates for the second curve, use
 # parameter ``x2``.
 
-x1 = np.linspace(0, 4, 100)
+x1 = np.linspace(0, 4, 10)
+y1 = 0.5 * np.cos(3 * x1)
 x2 = np.array(
     [0, 0.21, 0.4, 0.63, 0.89, 1.18, 1.45, 1.69, 1.96, 2.26, 2.61, 3.23, 3.49, 4.0]
 )
-y1 = 0.5 * np.cos(3 * x1)
 y2 = 0.5 * np.cos(3 * x2)
 
 fig = pygmt.Figure()
@@ -97,11 +97,12 @@
     label="y1(x1)",
     label2="y2(x2)",
 )
+
 # Mark sampling points
 fig.plot(x=x1, y=y1, style="c0.1c", fill="darkred")
 fig.plot(x=x2, y=y2, style="c0.1c", fill="darkblue")
 
 fig.legend()
-
+fig.show()
 
 # sphinx_gallery_thumbnail_number = 1

From 22cf9608f83eaae7b7884efc7af8e7b33f53ea19 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Wed, 24 Jun 2026 16:21:13 +0200
Subject: [PATCH 03/21] Fix input data

---
 examples/gallery/lines/fill_areas_between_curves.py | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index 36d9ab9015d..49e74486ad3 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -75,11 +75,9 @@
 # x-coordinates. For providing the x-coordinates for the second curve, use
 # parameter ``x2``.
 
-x1 = np.linspace(0, 4, 10)
-y1 = 0.5 * np.cos(3 * x1)
-x2 = np.array(
-    [0, 0.21, 0.4, 0.63, 0.89, 1.18, 1.45, 1.69, 1.96, 2.26, 2.61, 3.23, 3.49, 4.0]
-)
+x1 = np.linspace(0, 4, 100)
+y1 = np.sin(5 * x1)
+x2 = np.array([0, 0.21, 0.4, 0.63, 0.89, 1.18, 1.45, 1.69, 1.96, 2.26, 2.61, 3.23, 3.49, 4.0])
 y2 = 0.5 * np.cos(3 * x2)
 
 fig = pygmt.Figure()

From 71ff233534dcdb9a74ef1bd58abb012546b205a2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Wed, 24 Jun 2026 16:51:42 +0200
Subject: [PATCH 04/21] Adjust input data

---
 .../gallery/lines/fill_areas_between_curves.py | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index 49e74486ad3..b95e010f807 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -75,13 +75,13 @@
 # x-coordinates. For providing the x-coordinates for the second curve, use
 # parameter ``x2``.
 
-x1 = np.linspace(0, 4, 100)
-y1 = np.sin(5 * x1)
-x2 = np.array([0, 0.21, 0.4, 0.63, 0.89, 1.18, 1.45, 1.69, 1.96, 2.26, 2.61, 3.23, 3.49, 4.0])
-y2 = 0.5 * np.cos(3 * x2)
+x1 = np.arange(-10, 10.2, 0.2)
+y1 = np.sin(2 * x)
+x2 = np.array([-10, -8.21, -7.4, -6.63, -5.89, -4.18, -3.45, -2.69, -1.96, 0.26, 1.61, 2.23, 3.49, 4.0, 5.28, 6.79, 7.12, 8.25, 9.13, 10])
+y2 = 0.5 * np.cos(2 * x2)
 
 fig = pygmt.Figure()
-fig.basemap(region=[0, 4, -1.2, 1.2], projection="X10c/5c", frame=True)
+fig.basemap(region=[-10, 10, -5, 5], projection="X15c/5c", frame=True)
 
 fig.fill_between(
     x=x1,
@@ -90,15 +90,15 @@
     y2=y2,
     fill="orange",
     fill2="steelblue",
-    pen="1p,darkred",
-    pen2="1p,darkblue",
+    pen="1p,darkred,solid",
+    pen2="1p,darkblue,solid",
     label="y1(x1)",
     label2="y2(x2)",
 )
 
 # Mark sampling points
-fig.plot(x=x1, y=y1, style="c0.1c", fill="darkred")
-fig.plot(x=x2, y=y2, style="c0.1c", fill="darkblue")
+fig.plot(x=x1, y=y1, style="c0.1c", fill="magenta")
+fig.plot(x=x2, y=y2, style="c0.1c", fill="cyan")
 
 fig.legend()
 fig.show()

From 01217f3b3f9d53a940a184bb93e4f7fa3c7adb12 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Wed, 24 Jun 2026 16:55:34 +0200
Subject: [PATCH 05/21] Fix code style - maybe better exception here

---
 .../lines/fill_areas_between_curves.py        | 25 ++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index b95e010f807..432e0aebaba 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -77,7 +77,30 @@
 
 x1 = np.arange(-10, 10.2, 0.2)
 y1 = np.sin(2 * x)
-x2 = np.array([-10, -8.21, -7.4, -6.63, -5.89, -4.18, -3.45, -2.69, -1.96, 0.26, 1.61, 2.23, 3.49, 4.0, 5.28, 6.79, 7.12, 8.25, 9.13, 10])
+x2 = np.array(
+    [
+        -10,
+        -8.21,
+        -7.4,
+        -6.63,
+        -5.89,
+        -4.18,
+        -3.45,
+        -2.69,
+        -1.96,
+        0.26,
+        1.61,
+        2.23,
+        3.49,
+        4.0,
+        5.28,
+        6.79,
+        7.12,
+        8.25,
+        9.13,
+        10,
+    ]
+)
 y2 = 0.5 * np.cos(2 * x2)
 
 fig = pygmt.Figure()

From 4b4a5f1ad8a3a9ac64cf50d21b22208392615d05 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Wed, 24 Jun 2026 17:00:44 +0200
Subject: [PATCH 06/21] Fix typo in code

---
 examples/gallery/lines/fill_areas_between_curves.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index 432e0aebaba..7324927827b 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -76,7 +76,7 @@
 # parameter ``x2``.
 
 x1 = np.arange(-10, 10.2, 0.2)
-y1 = np.sin(2 * x)
+y1 = np.sin(2 * x1)
 x2 = np.array(
     [
         -10,

From 545fcdeb6e69ddd6eb36987a171e590a2987b138 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Wed, 24 Jun 2026 18:59:24 +0200
Subject: [PATCH 07/21] Adjust region, color and y2 curve

---
 examples/gallery/lines/fill_areas_between_curves.py | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index 7324927827b..f61eece705f 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -25,7 +25,7 @@
 # ``label`` and ``label2`` parameters to set the corresponding legend entries.
 
 fig = pygmt.Figure()
-fig.basemap(region=[-10, 10, -5, 5], projection="X15c/5c", frame=True)
+fig.basemap(region=[-10, 10, -3.5, 3.5], projection="X15c/5c", frame=True)
 
 fig.fill_between(
     x=x, y=y1, y2=y2, fill="orange", fill2="steelblue", label="y1(x)", label2="y2(x)"
@@ -39,7 +39,7 @@
 # ``pen2`` parameters to set different lines for the two curves y1 and y2, respectively.
 
 fig = pygmt.Figure()
-fig.basemap(region=[-10, 10, -5, 5], projection="X15c/5c", frame=True)
+fig.basemap(region=[-10, 10, -3.5, 3.5], projection="X15c/5c", frame=True)
 fig.fill_between(
     x=x,
     y=y1,
@@ -56,7 +56,7 @@
 # To compare a curve y1 to a horizontal line, pass the desired y-level to ``y2``.
 
 fig = pygmt.Figure()
-fig.basemap(region=[-10, 10, -5, 5], projection="X15c/5c", frame=True)
+fig.basemap(region=[-10, 10, -3.5, 3.5], projection="X15c/5c", frame=True)
 
 fig.fill_between(
     x=x,
@@ -101,10 +101,10 @@
         10,
     ]
 )
-y2 = 0.5 * np.cos(2 * x2)
+y2 = 0.5 * np.cos(x2 / 2)
 
 fig = pygmt.Figure()
-fig.basemap(region=[-10, 10, -5, 5], projection="X15c/5c", frame=True)
+fig.basemap(region=[-10, 10, -3.5, 3.5], projection="X15c/5c", frame=True)
 
 fig.fill_between(
     x=x1,
@@ -120,7 +120,7 @@
 )
 
 # Mark sampling points
-fig.plot(x=x1, y=y1, style="c0.1c", fill="magenta")
+fig.plot(x=x1, y=y1, style="c0.1c", fill="pink")
 fig.plot(x=x2, y=y2, style="c0.1c", fill="cyan")
 
 fig.legend()

From ed0d978999d45a4acd8740875e4c9068088e6f9b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Wed, 24 Jun 2026 19:22:54 +0200
Subject: [PATCH 08/21] Include 'legend-pen'

---
 examples/gallery/lines/fill_areas_between_curves.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index f61eece705f..c7cfd11c5dd 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -117,6 +117,7 @@
     pen2="1p,darkblue,solid",
     label="y1(x1)",
     label2="y2(x2)",
+    # legend_pen="5p",
 )
 
 # Mark sampling points

From 7b12e51954deaa7047d3dce1bb902539ea0ab4f3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Wed, 24 Jun 2026 19:47:25 +0200
Subject: [PATCH 09/21] Exclude line length limit locally

---
 .../lines/fill_areas_between_curves.py        | 25 +------------------
 1 file changed, 1 insertion(+), 24 deletions(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index c7cfd11c5dd..b835f95ef18 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -77,30 +77,7 @@
 
 x1 = np.arange(-10, 10.2, 0.2)
 y1 = np.sin(2 * x1)
-x2 = np.array(
-    [
-        -10,
-        -8.21,
-        -7.4,
-        -6.63,
-        -5.89,
-        -4.18,
-        -3.45,
-        -2.69,
-        -1.96,
-        0.26,
-        1.61,
-        2.23,
-        3.49,
-        4.0,
-        5.28,
-        6.79,
-        7.12,
-        8.25,
-        9.13,
-        10,
-    ]
-)
+x2 = np.array([-10, -8.21, -7.4, -6.63, -5.89, -4.18, -3.45, -2.69, -1.96, 0.26, 1.61, 2.23, 3.49, 4.0, 5.28, 6.79, 7.12, 8.25, 9.13, 10,])  # noqa: E501
 y2 = 0.5 * np.cos(x2 / 2)
 
 fig = pygmt.Figure()

From 4e6510f78dd76d30c2e987fc0e273ed642152132 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Wed, 24 Jun 2026 20:27:06 +0200
Subject: [PATCH 10/21] Try using random numbers

---
 examples/gallery/lines/fill_areas_between_curves.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index b835f95ef18..60b7020a3a2 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -77,7 +77,10 @@
 
 x1 = np.arange(-10, 10.2, 0.2)
 y1 = np.sin(2 * x1)
-x2 = np.array([-10, -8.21, -7.4, -6.63, -5.89, -4.18, -3.45, -2.69, -1.96, 0.26, 1.61, 2.23, 3.49, 4.0, 5.28, 6.79, 7.12, 8.25, 9.13, 10,])  # noqa: E501
+# Line limit still applies
+x2 = np.array([-9, -8.21, -7.4, -6.63, -5.89, -4.18, -3.45, -2.69, -1.96, 0.26, 1.61, 2.23, 3.49, 4.0, 5.28, 6.79, 7.12, 8.25, 9.13, 9])  # noqa: E501
+# Partly Segmentation fault problem (at least on Windows)
+x2 = np.sort((np.random.rand(20) - 0.5) * 20)
 y2 = 0.5 * np.cos(x2 / 2)
 
 fig = pygmt.Figure()

From cb6b6fcd8b92cb697d433abc187dc4c1e93724c7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Wed, 24 Jun 2026 20:32:49 +0200
Subject: [PATCH 11/21] Change back to manual list array for y2

---
 examples/gallery/lines/fill_areas_between_curves.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index 60b7020a3a2..a394ea051dd 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -77,10 +77,10 @@
 
 x1 = np.arange(-10, 10.2, 0.2)
 y1 = np.sin(2 * x1)
-# Line limit still applies
-x2 = np.array([-9, -8.21, -7.4, -6.63, -5.89, -4.18, -3.45, -2.69, -1.96, 0.26, 1.61, 2.23, 3.49, 4.0, 5.28, 6.79, 7.12, 8.25, 9.13, 9])  # noqa: E501
 # Partly Segmentation fault problem (at least on Windows)
 x2 = np.sort((np.random.rand(20) - 0.5) * 20)
+# Line limit still applies
+x2 = np.array([-9, -8.21, -7.4, -6.63, -5.89, -4.18, -3.45, -2.69, -1.96, 0.26, 1.61, 2.23, 3.49, 4.0, 5.28, 6.79, 7.12, 8.25, 9.13, 9])  # noqa: E501
 y2 = 0.5 * np.cos(x2 / 2)
 
 fig = pygmt.Figure()

From b5668766125faa07449f2724890f61ee0e2d88b1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Wed, 24 Jun 2026 21:03:42 +0200
Subject: [PATCH 12/21] Use complete plotting x region

---
 examples/gallery/lines/fill_areas_between_curves.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index a394ea051dd..6ceac2c3978 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -80,7 +80,7 @@
 # Partly Segmentation fault problem (at least on Windows)
 x2 = np.sort((np.random.rand(20) - 0.5) * 20)
 # Line limit still applies
-x2 = np.array([-9, -8.21, -7.4, -6.63, -5.89, -4.18, -3.45, -2.69, -1.96, 0.26, 1.61, 2.23, 3.49, 4.0, 5.28, 6.79, 7.12, 8.25, 9.13, 9])  # noqa: E501
+x2 = np.array([-10, -8.21, -7.4, -6.63, -5.89, -4.18, -3.45, -2.69, -1.96, 0.26, 1.61, 2.23, 3.49, 4.0, 5.28, 6.79, 7.12, 8.25, 9.13, 10])  # noqa: E501
 y2 = 0.5 * np.cos(x2 / 2)
 
 fig = pygmt.Figure()

From 1ea695d78a0db191bead4f813b27829875f88033 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Wed, 24 Jun 2026 22:21:40 +0200
Subject: [PATCH 13/21] Use consistent curves

---
 examples/gallery/lines/fill_areas_between_curves.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index 6ceac2c3978..4f0b39f0924 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -76,12 +76,12 @@
 # parameter ``x2``.
 
 x1 = np.arange(-10, 10.2, 0.2)
-y1 = np.sin(2 * x1)
+y1 = np.sin(3 * x1)
 # Partly Segmentation fault problem (at least on Windows)
 x2 = np.sort((np.random.rand(20) - 0.5) * 20)
 # Line limit still applies
 x2 = np.array([-10, -8.21, -7.4, -6.63, -5.89, -4.18, -3.45, -2.69, -1.96, 0.26, 1.61, 2.23, 3.49, 4.0, 5.28, 6.79, 7.12, 8.25, 9.13, 10])  # noqa: E501
-y2 = 0.5 * np.cos(x2 / 2)
+y2 = np.sin(x2 / 2)
 
 fig = pygmt.Figure()
 fig.basemap(region=[-10, 10, -3.5, 3.5], projection="X15c/5c", frame=True)

From 208df32fb743b5dd93a1dc012a1be72e3e829d3d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Thu, 25 Jun 2026 08:03:35 +0200
Subject: [PATCH 14/21] Use 'legend_pen'

---
 examples/gallery/lines/fill_areas_between_curves.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index 4f0b39f0924..af4ed662046 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -73,7 +73,9 @@
 # %%
 # Now, we use two non-co-registered curves, e.g., the two curves have different
 # x-coordinates. For providing the x-coordinates for the second curve, use
-# parameter ``x2``.
+# parameter ``x2``.  Via the ``legend_pen`` parameter the appearence in the legend
+# can be changed to draw the legend entries as colored lines (using the fill colors)
+# instead of filled boxes.
 
 x1 = np.arange(-10, 10.2, 0.2)
 y1 = np.sin(3 * x1)
@@ -97,7 +99,7 @@
     pen2="1p,darkblue,solid",
     label="y1(x1)",
     label2="y2(x2)",
-    # legend_pen="5p",
+    legend_pen="5p",
 )
 
 # Mark sampling points

From 38a2f84bae54b72bc68e3655eff89ae6746e067c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Thu, 25 Jun 2026 08:56:24 +0200
Subject: [PATCH 15/21] Restructure example

---
 .../lines/fill_areas_between_curves.py        | 72 ++++++++-----------
 1 file changed, 29 insertions(+), 43 deletions(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index af4ed662046..4efd5ee5c79 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -5,6 +5,13 @@
 y2. Different fills (colors or patterns) can be used for the areas y1 > y2 and
 y1 < y2. Optionally, the curves can be drawn. The two curves can be co-registered or
 have different x-coordinates.
+
+For filling the areas between the two curves use the ``fill`` and ``fill2`` parameters
+to set different fills for areas with y1 > y2 and y1 < y2, respectively. Use the  ``label``
+and ``label2`` parameters to set the corresponding legend entries. In addition to filling
+the areas, we can draw the curves. Use the ``pen`` and  ``pen2`` parameters to set different
+lines for the two curves y1 and y2, respectively.
+
 To plot an anomaly along a track use :meth:`pygmt.Figure.wiggle` and see the gallery
 example :doc:`Wiggle along tracks </gallery/lines/wiggle>`.
 """
@@ -14,36 +21,27 @@
 import pygmt
 
 # Generate some test data
-x = np.arange(-10, 10.2, 0.1)
+x = np.arange(-10, 10.2, 0.2)
 y1 = np.sin(3 * x)
 y2 = np.sin(x / 2)
 
-
-# %%
-# Fill the areas between the two curves. Use the ``fill`` and ``fill2`` parameters to
-# set different fills for areas with y1 > y2 and y1 < y2, respectively. Use the
-# ``label`` and ``label2`` parameters to set the corresponding legend entries.
-
-fig = pygmt.Figure()
-fig.basemap(region=[-10, 10, -3.5, 3.5], projection="X15c/5c", frame=True)
-
-fig.fill_between(
-    x=x, y=y1, y2=y2, fill="orange", fill2="steelblue", label="y1(x)", label2="y2(x)"
-)
-fig.legend()
-fig.show()
+# Partly Segmentation fault problem (at least on Windows)
+x3 = np.sort((np.random.rand(20) - 0.5) * 20)
+# Line limit still applies
+x3 = np.array([-10, -8.21, -7.4, -6.63, -5.89, -4.18, -3.45, -2.69, -1.96, 0.26, 1.61, 2.23, 3.49, 4.0, 5.28, 6.79, 7.12, 8.25, 9.13, 10])  # noqa: E501
+y3 = np.sin(x3 / 2)
 
 
 # %%
-# In addition to filling the areas, we can draw the curves. Use the ``pen`` and
-# ``pen2`` parameters to set different lines for the two curves y1 and y2, respectively.
+# To compare a curve y1(x) to a horizontal line, pass the desired y-level to ``y2``.
 
 fig = pygmt.Figure()
 fig.basemap(region=[-10, 10, -3.5, 3.5], projection="X15c/5c", frame=True)
+
 fig.fill_between(
     x=x,
     y=y1,
-    y2=y2,
+    y2=0.42,
     fill="p8",
     fill2="p17",
     pen="1p,black,solid",
@@ -53,20 +51,16 @@
 
 
 # %%
-# To compare a curve y1 to a horizontal line, pass the desired y-level to ``y2``.
+# To compare two co-registered curves y1(x) and y2(x) pass a sequence with the same length
+# as the inputs for ``x`` and ``y`` to ``y2``.
 
 fig = pygmt.Figure()
 fig.basemap(region=[-10, 10, -3.5, 3.5], projection="X15c/5c", frame=True)
 
 fig.fill_between(
-    x=x,
-    y=y1,
-    y2=0.42,
-    fill="p8",
-    fill2="p17",
-    pen="1p,black,solid",
-    pen2="1p,black,dashed",
+    x=x, y=y1, y2=y2, fill="orange", fill2="steelblue", label="y1(x)", label2="y2(x)"
 )
+fig.legend()
 fig.show()
 
 
@@ -77,36 +71,28 @@
 # can be changed to draw the legend entries as colored lines (using the fill colors)
 # instead of filled boxes.
 
-x1 = np.arange(-10, 10.2, 0.2)
-y1 = np.sin(3 * x1)
-# Partly Segmentation fault problem (at least on Windows)
-x2 = np.sort((np.random.rand(20) - 0.5) * 20)
-# Line limit still applies
-x2 = np.array([-10, -8.21, -7.4, -6.63, -5.89, -4.18, -3.45, -2.69, -1.96, 0.26, 1.61, 2.23, 3.49, 4.0, 5.28, 6.79, 7.12, 8.25, 9.13, 10])  # noqa: E501
-y2 = np.sin(x2 / 2)
-
 fig = pygmt.Figure()
 fig.basemap(region=[-10, 10, -3.5, 3.5], projection="X15c/5c", frame=True)
 
 fig.fill_between(
-    x=x1,
+    x=x,
     y=y1,
-    x2=x2,
-    y2=y2,
+    x2=x3,
+    y2=y3,
     fill="orange",
     fill2="steelblue",
     pen="1p,darkred,solid",
     pen2="1p,darkblue,solid",
-    label="y1(x1)",
-    label2="y2(x2)",
-    legend_pen="5p",
+    label="y1(x)",
+    label2="y3(x3)",
+    legend_pen=True,
 )
 
 # Mark sampling points
-fig.plot(x=x1, y=y1, style="c0.1c", fill="pink")
-fig.plot(x=x2, y=y2, style="c0.1c", fill="cyan")
+fig.plot(x=x, y=y1, style="c0.1c", fill="pink")
+fig.plot(x=x3, y=y3, style="c0.1c", fill="cyan")
 
 fig.legend()
 fig.show()
 
-# sphinx_gallery_thumbnail_number = 1
+# sphinx_gallery_thumbnail_number = 3

From 41d4ba63ed0b51ea1d588035bf367a3d714dfc91 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Thu, 25 Jun 2026 09:06:28 +0200
Subject: [PATCH 16/21] Improve intro text

---
 .../lines/fill_areas_between_curves.py        | 23 +++++++++----------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index 4efd5ee5c79..950e5b758ae 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -3,17 +3,16 @@
 ========================
 The :meth:`pygmt.Figure.fill_between` method fills the area between two curves y1 and
 y2. Different fills (colors or patterns) can be used for the areas y1 > y2 and
-y1 < y2. Optionally, the curves can be drawn. The two curves can be co-registered or
-have different x-coordinates.
+y1 < y2. The two curves can be co-registered or have different x-coordinates. To plot
+an anomaly along a track use :meth:`pygmt.Figure.wiggle` and see the gallery example
+:doc:`Wiggle along tracks </gallery/lines/wiggle>`.
 
 For filling the areas between the two curves use the ``fill`` and ``fill2`` parameters
-to set different fills for areas with y1 > y2 and y1 < y2, respectively. Use the  ``label``
-and ``label2`` parameters to set the corresponding legend entries. In addition to filling
-the areas, we can draw the curves. Use the ``pen`` and  ``pen2`` parameters to set different
-lines for the two curves y1 and y2, respectively.
+to set different fills for the areas with y1 > y2 and y1 < y2, respectively. Use the
+``label`` and ``label2`` parameters to set the corresponding legend entries. In addition
+to filling the areas, we can draw the outline curves. Use the ``pen`` and  ``pen2``
+parameters to set different lines for the two curves y1 and y2, respectively.
 
-To plot an anomaly along a track use :meth:`pygmt.Figure.wiggle` and see the gallery
-example :doc:`Wiggle along tracks </gallery/lines/wiggle>`.
 """
 
 # %%
@@ -26,7 +25,7 @@
 y2 = np.sin(x / 2)
 
 # Partly Segmentation fault problem (at least on Windows)
-x3 = np.sort((np.random.rand(20) - 0.5) * 20)
+x3 = np.sort((np.random.Generator(20) - 0.5) * 20)
 # Line limit still applies
 x3 = np.array([-10, -8.21, -7.4, -6.63, -5.89, -4.18, -3.45, -2.69, -1.96, 0.26, 1.61, 2.23, 3.49, 4.0, 5.28, 6.79, 7.12, 8.25, 9.13, 10])  # noqa: E501
 y3 = np.sin(x3 / 2)
@@ -51,8 +50,8 @@
 
 
 # %%
-# To compare two co-registered curves y1(x) and y2(x) pass a sequence with the same length
-# as the inputs for ``x`` and ``y`` to ``y2``.
+# To compare two co-registered curves y1(x) and y2(x) pass a sequence with the same
+# length as the inputs for ``x`` and ``y`` to ``y2``.
 
 fig = pygmt.Figure()
 fig.basemap(region=[-10, 10, -3.5, 3.5], projection="X15c/5c", frame=True)
@@ -69,7 +68,7 @@
 # x-coordinates. For providing the x-coordinates for the second curve, use
 # parameter ``x2``.  Via the ``legend_pen`` parameter the appearence in the legend
 # can be changed to draw the legend entries as colored lines (using the fill colors)
-# instead of filled boxes.
+# instead of filled and outlined boxes.
 
 fig = pygmt.Figure()
 fig.basemap(region=[-10, 10, -3.5, 3.5], projection="X15c/5c", frame=True)

From 18de8be735dd7ffe8a1abbe0cb99f2d2f310effb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Thu, 25 Jun 2026 09:12:24 +0200
Subject: [PATCH 17/21] Fix random  numbers

---
 examples/gallery/lines/fill_areas_between_curves.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index 950e5b758ae..bb5aace6e31 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -25,7 +25,7 @@
 y2 = np.sin(x / 2)
 
 # Partly Segmentation fault problem (at least on Windows)
-x3 = np.sort((np.random.Generator(20) - 0.5) * 20)
+# x3 = np.sort((np.random.rand(20) - 0.5) * 20)
 # Line limit still applies
 x3 = np.array([-10, -8.21, -7.4, -6.63, -5.89, -4.18, -3.45, -2.69, -1.96, 0.26, 1.61, 2.23, 3.49, 4.0, 5.28, 6.79, 7.12, 8.25, 9.13, 10])  # noqa: E501
 y3 = np.sin(x3 / 2)

From 47a1d2ec44947756754ce818c9a394526b4b92a1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?=
 <94163266+yvonnefroehlich@users.noreply.github.com>
Date: Thu, 25 Jun 2026 10:40:02 +0200
Subject: [PATCH 18/21] Use only one decimal digit for x3

Co-authored-by: Dongdong Tian <seisman.info@gmail.com>
---
 examples/gallery/lines/fill_areas_between_curves.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index bb5aace6e31..36370fe51a6 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -27,7 +27,7 @@
 # Partly Segmentation fault problem (at least on Windows)
 # x3 = np.sort((np.random.rand(20) - 0.5) * 20)
 # Line limit still applies
-x3 = np.array([-10, -8.21, -7.4, -6.63, -5.89, -4.18, -3.45, -2.69, -1.96, 0.26, 1.61, 2.23, 3.49, 4.0, 5.28, 6.79, 7.12, 8.25, 9.13, 10])  # noqa: E501
+x3 = np.array([-10, -8.2, -7.4, -6.6, -5.8, -4.1, -3.4, -2.6, -1.9, 0.2, 1.6, 2.2, 3.4, 4.0, 5.2, 6.7, 7.1, 8.2, 9.1, 10])  # noqa: E501
 y3 = np.sin(x3 / 2)
 
 

From 398f35600e036f2a091cdeb5a0c3ade43b72196b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Thu, 25 Jun 2026 11:31:26 +0200
Subject: [PATCH 19/21] Shift and increase step of the curve for other sampling
 points

---
 examples/gallery/lines/fill_areas_between_curves.py | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index 36370fe51a6..1b1185df7f4 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -24,10 +24,7 @@
 y1 = np.sin(3 * x)
 y2 = np.sin(x / 2)
 
-# Partly Segmentation fault problem (at least on Windows)
-# x3 = np.sort((np.random.rand(20) - 0.5) * 20)
-# Line limit still applies
-x3 = np.array([-10, -8.2, -7.4, -6.6, -5.8, -4.1, -3.4, -2.6, -1.9, 0.2, 1.6, 2.2, 3.4, 4.0, 5.2, 6.7, 7.1, 8.2, 9.1, 10])  # noqa: E501
+x3 = np.arange(-10, 10.4, 0.5) - 0.15
 y3 = np.sin(x3 / 2)
 
 

From 3a605333b25e9113349aa4146e939981bd97e20f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?= <yvonne.froehlich@kit.edu>
Date: Thu, 25 Jun 2026 11:40:51 +0200
Subject: [PATCH 20/21] Increase sampling

---
 examples/gallery/lines/fill_areas_between_curves.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index 1b1185df7f4..3cff739e100 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -20,11 +20,11 @@
 import pygmt
 
 # Generate some test data
-x = np.arange(-10, 10.2, 0.2)
+x = np.arange(-10, 10.2, 0.15)
 y1 = np.sin(3 * x)
 y2 = np.sin(x / 2)
 
-x3 = np.arange(-10, 10.4, 0.5) - 0.15
+x3 = np.arange(-10, 10.4, 0.5) - 0.13
 y3 = np.sin(x3 / 2)
 
 

From 6306da116ba4ca556b3032aa90ca0d789c2876f1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yvonne=20Fr=C3=B6hlich?=
 <94163266+yvonnefroehlich@users.noreply.github.com>
Date: Thu, 25 Jun 2026 11:50:43 +0200
Subject: [PATCH 21/21] Fix typo

---
 examples/gallery/lines/fill_areas_between_curves.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/gallery/lines/fill_areas_between_curves.py b/examples/gallery/lines/fill_areas_between_curves.py
index 3cff739e100..db30e125f5a 100644
--- a/examples/gallery/lines/fill_areas_between_curves.py
+++ b/examples/gallery/lines/fill_areas_between_curves.py
@@ -63,7 +63,7 @@
 # %%
 # Now, we use two non-co-registered curves, e.g., the two curves have different
 # x-coordinates. For providing the x-coordinates for the second curve, use
-# parameter ``x2``.  Via the ``legend_pen`` parameter the appearence in the legend
+# parameter ``x2``.  Via the ``legend_pen`` parameter the appearance in the legend
 # can be changed to draw the legend entries as colored lines (using the fill colors)
 # instead of filled and outlined boxes.