Add an example for different line styles (#604)

Author: seisman

doc/conf.py

@@ -60,6 +60,7 @@
     "gallery_dirs": ["gallery", "tutorials", "projections"],
     "subsection_order": ExplicitOrder(
         [
+            "../examples/gallery/line",
             "../examples/gallery/coast",
             "../examples/gallery/plot",
             "../examples/gallery/grid",

examples/gallery/line/README.txt

@@ -0,0 +1,2 @@
+Lines
+-----

examples/gallery/line/linestyles.py

@@ -0,0 +1,42 @@
+"""
+Line styles
+-----------
+
+The :meth:`pygmt.Figure.plot` method can plot lines in different styles.
+The default line style is a 0.25-point wide, black, solid line, and can be
+customized via the ``pen`` argument.
+
+A *pen* in GMT has three attributes: *width*, *color*, and *style*.
+The *style* attribute controls the appearance of the line.
+Giving “dotted” or “.” yields a dotted line, whereas a dashed pen is requested
+with “dashed” or “-”. Also combinations of dots and dashes, like “.-” for a
+dot-dashed line, are allowed.
+
+For more advanced *pen* attributes, see the GMT cookbook
+:gmt-docs:`cookbook/features.html#wpen-attrib`.
+
+"""
+
+import numpy as np
+import pygmt
+
+# Generate a sample line for plotting
+x = np.linspace(0, 10, 500)
+y = np.sin(x)
+
+fig = pygmt.Figure()
+fig.basemap(region=[0, 10, -3, 3], projection="X15c/8c", frame=["xaf", "yaf", "WSrt"])
+
+# Plot the line using the default line style
+fig.plot(x=x, y=y)
+
+# Plot the lines using different line styles
+fig.plot(x=x, y=y + 1.5, pen="1p,red,-")
+fig.plot(x=x, y=y + 1.0, pen="2p,blue,.")
+fig.plot(x=x, y=y + 0.5, pen="1p,red,-.")
+
+fig.plot(x=x, y=y - 0.5, pen="2p,blue,..-")
+fig.plot(x=x, y=y - 1.0, pen="3p,tomato,--.")
+fig.plot(x=x, y=y - 1.5, pen="3p,tomato,4_2:2p")
+
+fig.show()