Merge pull request matplotlib#15555 from anntzer/pgfusage

Add pgf to list of builtin backends in docs.

Author: timhoffm

tutorials/introductory/usage.py

@@ -391,20 +391,17 @@ def my_plotter(ax, data1, data2, param_dict):
 # ========  =========  =======================================================
 # AGG       png        raster_ graphics -- high quality images using the
 #                      `Anti-Grain Geometry`_ engine
-# PS        ps,        vector_ graphics -- Postscript_ output
-#           eps
 # PDF       pdf        vector_ graphics -- `Portable Document Format`_
+# PS        ps, eps    vector_ graphics -- Postscript_ output
 # SVG       svg        vector_ graphics -- `Scalable Vector Graphics`_
+# PGF       pgf, pdf   vector_ graphics -- using the pgf_ package
 # Cairo     png, ps,   raster_ or vector_ graphics -- using the Cairo_ library
 #           pdf, svg
 # ========  =========  =======================================================
 #
 # To save plots using the non-interactive backends, use the
 # ``matplotlib.pyplot.savefig('filename')`` method.
 #
-# To save plots using the non-interactive backends, use the
-# ``matplotlib.pyplot.savefig('filename')`` method.
-#
 # And here are the user interfaces and renderer combinations supported;
 # these are *interactive backends*, capable of displaying to the screen
 # and of using appropriate renderers from the table above to write to
@@ -444,9 +441,10 @@ def my_plotter(ax, data1, data2, param_dict):
 #    'qt5agg' are equivalent.
 #
 # .. _`Anti-Grain Geometry`: http://antigrain.com/
-# .. _Postscript: https://en.wikipedia.org/wiki/PostScript
 # .. _`Portable Document Format`: https://en.wikipedia.org/wiki/Portable_Document_Format
+# .. _Postscript: https://en.wikipedia.org/wiki/PostScript
 # .. _`Scalable Vector Graphics`: https://en.wikipedia.org/wiki/Scalable_Vector_Graphics
+# .. _pgf: https://ctan.org/pkg/pgf
 # .. _Cairo: https://www.cairographics.org
 # .. _PyGObject: https://wiki.gnome.org/action/show/Projects/PyGObject
 # .. _pycairo: https://www.cairographics.org/pycairo/