Gallery example "Velocity arrows and confidence ellipses": Improve ar…

…gument passed to "spec" (#3245)

examples/gallery/seismology/velo_arrow_ellipse.py

@@ -2,12 +2,12 @@
 Velocity arrows and confidence ellipses
 =======================================
 
-The :meth:`pygmt.Figure.velo` method can be used to plot mean velocity arrows
-and confidence ellipses. The example below plots red velocity arrows with
-light-blue confidence ellipses outlined in red with the east_velocity x
-north_velocity used for the station names. Note that the velocity arrows are
-scaled by 0.2 and the 39% confidence limit will give an ellipse which fits
-inside a rectangle of dimension east_sigma by north_sigma.
+The :meth:`pygmt.Figure.velo` method can be used to plot mean velocity arrows and
+confidence ellipses. The example below plots red velocity arrows with lightblue
+confidence ellipses outlined in red with the east_velocity x north_velocity used for
+the station names. Note that the velocity arrows are scaled by 0.2 and the 39%
+confidence limit will give an ellipse which fits inside a rectangle of dimension
+east_sigma by north_sigma.
 """
 
 # %%
@@ -30,12 +30,12 @@
 fig.velo(
     data=df,
     region=[-10, 8, -10, 6],
-    pen="0.6p,red",
+    projection="x0.8c",
+    frame=["WSne", "2g2f"],
+    spec="e0.2/0.39+f18",
     uncertaintyfill="lightblue1",
+    pen="0.6p,red",
     line=True,
-    spec="e0.2/0.39/18",
-    frame=["WSne", "2g2f"],
-    projection="x0.8c",
     vector="0.3c+p1p+e+gred",
 )