Merge remote-tracking branch 'igraph/develop' into develop

doc/examples_sphinx-gallery/spanning_trees.py

@@ -55,3 +55,8 @@
     edge_width=g.es["width"]
 )
 plt.show()
+
+# %%
+# .. note::
+#   To invert the y axis such that the root of the tree is on top of the plot,
+#   you can call `ax.invert_yaxis()` before `plt.show()`.

doc/source/tutorial.rst

@@ -691,6 +691,11 @@ If you prefer to use `matplotlib`_ as a plotting engine, create an axes and use
    :alt: The visual representation of our social network (matplotlib backend)
    :align: center
 
+.. note::
+   When plotting rooted trees, Cairo automatically puts the root on top of the image and
+   the leaves at the bottom. For `matplotlib`_, the root is usually at the bottom instead.
+   You can easily place the root on top by calling `ax.invert_yaxis()`.
+
 Hmm, this is not too pretty so far. A trivial addition would be to use the names as the
 vertex labels and to color the vertices according to the gender. Vertex labels are taken
 from the ``label`` attribute by default and vertex colors are determined by the

doc/source/visualisation.rst

@@ -129,6 +129,11 @@ You can then further manipulate the axes and figure however you like via the `ax
 called them). This variant does not use `Cairo`_ directly and might be lacking some features that are available in the
 `Cairo`_ backend: please open an issue on Github to request specific features.
 
+.. note::
+   When plotting rooted trees, Cairo automatically puts the root on top of the image and
+   the leaves at the bottom. For `matplotlib`_, the root is usually at the bottom instead.
+   You can easily place the root on top by calling `ax.invert_yaxis()`.
+
 Plotting via `matplotlib`_ makes it easy to combine igraph with other plots. For instance, if you want to have a figure
 with two panels showing different aspects of some data set, say a graph and a bar plot, you can easily do that::