Update a few tutorials to reduce building time (#871)

Use a lower-resolution earth relief grid to reduce the building time

Co-authored-by: Dongdong Tian <seisman.info@gmail.com>

examples/tutorials/3d-perspective-image.py

@@ -14,12 +14,12 @@
     To save the figure, use ``fig.savefig("figname.pdf")`` where ``"figname.pdf"``
     is the desired name and file extension for the saved figure.
 """
-# sphinx_gallery_thumbnail_number = 7
+# sphinx_gallery_thumbnail_number = 4
 
 import pygmt
 
 # Load sample earth relief data
-grid = pygmt.datasets.load_earth_relief(resolution="05m", region=[-108, -103, 35, 40])
+grid = pygmt.datasets.load_earth_relief(resolution="10m", region=[-108, -103, 35, 40])
 
 ########################################################################################
 # The :meth:`pygmt.Figure.grdview` method takes the ``grid`` input.
@@ -45,20 +45,6 @@
 
 ########################################################################################
 # The grid surface type can be set with the ``surftype`` parameter.
-
-fig = pygmt.Figure()
-fig.grdview(
-    grid=grid,
-    perspective=[130, 30],
-    frame=["xa", "ya", "WSnE"],
-    projection="M15c",
-    zsize="1.5c",
-    # Set the surftype to "surface"
-    surftype="s",
-)
-fig.show()
-
-########################################################################################
 # The default CPT is *turbo* and can be customized with the ``cmap`` parameter.
 
 fig = pygmt.Figure()
@@ -68,6 +54,7 @@
     frame=["xa", "yaf", "WSnE"],
     projection="M15c",
     zsize="1.5c",
+    # Set the surftype to "surface"
     surftype="s",
     # Set the CPT to "geo"
     cmap="geo",
@@ -94,55 +81,23 @@
 
 ########################################################################################
 # The ``perspective`` azimuth can be changed to set the direction that is "up"
-# in the figure.
+# in the figure. The ``contourpen`` parameter sets the pen used to draw contour lines
+# on the surface. :meth:`pygmt.Figure.colorbar` can be used to add a color bar to the
+# figure. The ``cmap`` parameter does not need to be passed again. To keep the color
+# bar's alignment similar to the figure, use ``True`` as the ``perspective`` parameter.
 
 fig = pygmt.Figure()
 fig.grdview(
     grid=grid,
     # Set the azimuth to -130 (230) degrees and the elevation to 30 degrees
     perspective=[-130, 30],
-    frame=["xa", "yaf", "WSnE"],
-    projection="M15c",
-    zsize="1.5c",
-    surftype="s",
-    cmap="geo",
-    plane="1000+ggrey",
-)
-fig.show()
-
-########################################################################################
-# The ``contourpen`` parameter sets the pen used to draw contour lines on the surface.
-
-fig = pygmt.Figure()
-fig.grdview(
-    grid=grid,
-    perspective=[-130, 30],
-    frame=["xaf", "yaf", "WSnE"],
-    projection="M15c",
-    zsize="1.5c",
-    surftype="s",
-    cmap="geo",
-    plane="1000+ggrey",
-    # Set the contour pen thickness to "0.5p"
-    contourpen="0.5p",
-)
-fig.show()
-
-########################################################################################
-# :meth:`pygmt.Figure.colorbar` can be used to add a color bar to the figure. The
-# ``cmap`` argument does not need to be passed again. To keep the color bar's alignment
-# similar to the figure, use ``True`` as the ``perspective`` argument.
-
-fig = pygmt.Figure()
-fig.grdview(
-    grid=grid,
-    perspective=[-130, 30],
     frame=["xaf", "yaf", "WSnE"],
     projection="M15c",
     zsize="1.5c",
     surftype="s",
     cmap="geo",
     plane="1000+ggrey",
+    # Set the contour pen thickness to "0.1p"
     contourpen="0.1p",
 )
 fig.colorbar(perspective=True, frame=["a500", "x+lElevation", "y+lm"])

examples/tutorials/earth-relief.py

@@ -20,9 +20,10 @@
 import pygmt
 
 ########################################################################################
-# Load sample Earth relief data for the entire globe at a resolution of 30 arc minutes.
-# The other available resolutions are show at :gmt-docs:`datasets/remote-data.html#global-earth-relief-grids`.
-grid = pygmt.datasets.load_earth_relief(resolution="30m")
+# Load sample Earth relief data for the entire globe at a resolution of 1 arc degree.
+# The other available resolutions are show
+# at :gmt-docs:`datasets/remote-data.html#global-earth-relief-grids`.
+grid = pygmt.datasets.load_earth_relief(resolution="01d")
 
 ########################################################################################
 # Create a plot
@@ -95,15 +96,15 @@
 #
 # In addition to providing global data, the ``region`` argument for
 # :meth:`pygmt.datasets.load_earth_relief` can be used to provide data for a specific
-# area. The ``region`` argument is required for resolutions at 5 arc minutes or higher, and
-# accepts a list (as in the example below) or a string. The geographic ranges are
+# area. The ``region`` argument is required for resolutions at 5 arc minutes or higher,
+# and accepts a list (as in the example below) or a string. The geographic ranges are
 # passed as *xmin*/*xmax*/*ymin*/*ymax*.
 #
-# The example below uses data with a 5 arc minute resolution, and plots it on a
+# The example below uses data with a 10 arc minute resolution, and plots it on a
 # 15 centimeter figure with a Mercator projection and a CPT set to *geo*.
 # ``frame="a"`` is used to add a frame to the figure.
 
-grid = pygmt.datasets.load_earth_relief(resolution="05m", region=[-14, 30, 35, 60])
+grid = pygmt.datasets.load_earth_relief(resolution="10m", region=[-14, 30, 35, 60])
 fig = pygmt.Figure()
 fig.grdimage(grid=grid, projection="M15c", frame="a", cmap="geo")
 fig.colorbar(frame=["a1000", "x+lElevation", "y+lm"])

examples/tutorials/regions.py

@@ -96,7 +96,7 @@
 fig.coast(
     region="d",
     projection="Cyl_stere/12c",
-    land="lightgray",
+    land="darkgray",
     water="white",
     borders="1/0.5p",
     shorelines="1/0.5p",
@@ -115,7 +115,7 @@
 fig.coast(
     region="g",
     projection="Cyl_stere/12c",
-    land="lightgray",
+    land="darkgray",
     water="white",
     borders="1/0.5p",
     shorelines="1/0.5p",