.. _example_10:

(10) A geographical bar graph plot
----------------------------------

Our next and perhaps most business-like example presents a
three-dimensional bar graph plot showing the geographic distribution of
all the languages of the world. The input data
was taken from `Ethnologue <https://www.ethnologue.com/>`_. We decide to plot a 3-D multi-band column
centered on each continent with a height that is proportional to the
languages used. We choose a plain
linear projection for the basemap and add the multi-band columns and text on top.
The different bands in the columns indicate how commonly the languages are used, from institutional languages to
languages threatened by extinction.  We use :doc:`gmtmath </gmtmath>` to sum up the total languages per continent.
The script also shows how to effectively use transparency of the boxes around the numbers
and in the shade surrounding the legend.
Our script that produces Figure 10 reads:

.. literalinclude:: /_verbatim/ex10.txt
   :language: bash

.. figure:: /_images/ex10.*
   :width: 500 px
   :align: center

   Geographical bar graph.
