restore compat with matplotlib <= 3.3

yt/visualization/plot_container.py

@@ -10,6 +10,7 @@
 from matplotlib.cm import get_cmap
 from matplotlib.font_manager import FontProperties
 from more_itertools.more import always_iterable
+from packaging.version import Version
 
 from yt._maintenance.deprecation import issue_deprecation_warning
 from yt.config import ytcfg
@@ -22,6 +23,7 @@
 
 from ._commons import validate_image_name
 
+MPL_VERSION = Version(matplotlib.__version__)
 try:
  import cmocean
 except ImportError:
@@ -239,13 +241,15 @@ def __init__(self, data_source, default_factory=None):
 
 _DEFAULT_FONT_PROPERTIES = {
  "family": "stixgeneral",
- "math_fontfamily": "cm",
  "size": 18,
  "fname": os.path.join(
  matplotlib.get_data_path(), "fonts", "ttf", "STIXGeneral.ttf"
  ),
 }
 
+if MPL_VERSION >= Version("3.4"):
+ _DEFAULT_FONT_PROPERTIES["math_fontfamily"] = "cm"
+
 
 class PlotContainer:
  """A container for generic plots"""