Merge pull request #21372 from meeseeksmachine/auto-backport-of-pr-20708-on-v3.5.x

timhoffm · web-flow · commit bc1d37c261fd · 2021-10-16T14:07:58.000+02:00
Backport PR #20708 on branch v3.5.x (Describe possible need for loading the 'lmodern' package when using PGF files)
diff --git a/lib/matplotlib/backends/backend_pgf.py b/lib/matplotlib/backends/backend_pgf.py
@@ -801,6 +801,10 @@ def _print_pgf_to_fh(self, fh, *, bbox_inches_restore=None):
 %% Make sure the required packages are loaded in your preamble
 %%   \\usepackage{pgf}
 %%
+%% Also ensure that all the required font packages are loaded; for instance,
+%% the lmodern package is sometimes necessary when using math font.
+%%   \\usepackage{lmodern}
+%%
 %% Figures using additional raster images can only be included by \\input if
 %% they are in the same directory as the main LaTeX file. For loading figures
 %% from other directories you can use the `import` package
diff --git a/tutorials/text/pgf.py b/tutorials/text/pgf.py
@@ -187,6 +187,12 @@
   using either the ``rasterized=True`` keyword, or ``.set_rasterized(True)`` as
   per :doc:`this example </gallery/misc/rasterization_demo>`.
 
+* Various math fonts are compiled and rendered only if corresponding font
+  packages are loaded. Specifically, when using ``\mathbf{}`` on Greek letters,
+  the default computer modern font may not contain them, in which case the
+  letter is not rendered. In such scenarios, the ``lmodern`` package should be
+  loaded.
+
 * If you still need help, please see :ref:`reporting-problems`
 
 .. _LaTeX: http://www.tug.org
