Add mechanism to deactivate LaTeX matplotlib rendering

2 files changed, 43 insertions, 17 deletions

diff --git a/src/python/doc/persistence_graphical_tools_user.rst b/src/python/doc/persistence_graphical_tools_user.rst
index b5a38eb1..5cdc2dca 100644
--- a/src/python/doc/persistence_graphical_tools_user.rst
+++ b/src/python/doc/persistence_graphical_tools_user.rst
@@ -90,3 +90,17 @@ If you want more information on a specific dimension, for instance:
     gudhi.plot_persistence_density(persistence=pers_diag,
         dimension=1, legend=True, axes=axes[1])
     plt.show()
+
+LaTeX support
+-------------
+
+By default, persistence graphical tools are using LaTeX support for matplotlib if available (cf.
+`matplotlib text rendering with LaTeX <https://matplotlib.org/3.3.0/tutorials/text/usetex.html>`_).
+It also requires `type1cm` LaTeX package (not detected by matplotlib).
+
+If you are facing issues with LaTeX rendering, you can still deactivate LaTeX rendering by saying:
+
+.. code-block:: python
+
+    import gudhi
+    gudhi.persistence_graphical_tools._gudhi_matplotlib_use_tex=False
diff --git a/src/python/gudhi/persistence_graphical_tools.py b/src/python/gudhi/persistence_graphical_tools.py
index c6766c70..cce091d5 100644
--- a/src/python/gudhi/persistence_graphical_tools.py
+++ b/src/python/gudhi/persistence_graphical_tools.py
@@ -20,6 +20,20 @@ __author__ = "Vincent Rouvreau, Bertrand Michel, Theo Lacombe"
 __copyright__ = "Copyright (C) 2016 Inria"
 __license__ = "MIT"
 
+@lru_cache(maxsize=1)
+def _matplotlib_can_use_tex():
+    """This function returns True if matplotlib can deal with LaTeX, False otherwise.
+    The returned value is cached.
+    """
+    try:
+        from matplotlib import checkdep_usetex
+        return checkdep_usetex(True)
+    except ImportError:
+        print("This function is not available, you may be missing matplotlib.")
+
+
+_gudhi_matplotlib_use_tex = _matplotlib_can_use_tex()
+
 
 def __min_birth_max_death(persistence, band=0.0):
     """This function returns (min_birth, max_death) from the persistence.
@@ -57,17 +71,6 @@ def _array_handler(a):
     else:
         return a
 
-@lru_cache(maxsize=1)
-def _matplotlib_can_use_tex():
-    """This function returns True if matplotlib can deal with LaTeX, False otherwise.
-    The returned value is cached.
-    """
-    try:
-        from matplotlib import checkdep_usetex
-        return checkdep_usetex(True)
-    except ImportError:
-        print("This function is not available, you may be missing matplotlib.")
-
 
 def plot_persistence_barcode(
     persistence=[],
@@ -117,10 +120,13 @@ def plot_persistence_barcode(
     try:
         import matplotlib.pyplot as plt
         import matplotlib.patches as mpatches
-        if _matplotlib_can_use_tex():
-            from matplotlib import rc
+        from matplotlib import rc
+        if _gudhi_matplotlib_use_tex:
             plt.rc('text', usetex=True)
             plt.rc('font', family='serif')
+        else:
+            plt.rc('text', usetex=False)
+            plt.rc('font', family='DejaVu Sans')
 
         if persistence_file != "":
             if path.isfile(persistence_file):
@@ -263,10 +269,13 @@ def plot_persistence_diagram(
     try:
         import matplotlib.pyplot as plt
         import matplotlib.patches as mpatches
-        if _matplotlib_can_use_tex():
-            from matplotlib import rc
+        from matplotlib import rc
+        if _gudhi_matplotlib_use_tex:
             plt.rc('text', usetex=True)
             plt.rc('font', family='serif')
+        else:
+            plt.rc('text', usetex=False)
+            plt.rc('font', family='DejaVu Sans')
 
         if persistence_file != "":
             if path.isfile(persistence_file):
@@ -436,10 +445,13 @@ def plot_persistence_density(
         import matplotlib.pyplot as plt
         import matplotlib.patches as mpatches
         from scipy.stats import kde
-        if _matplotlib_can_use_tex():
-            from matplotlib import rc
+        from matplotlib import rc
+        if _gudhi_matplotlib_use_tex:
             plt.rc('text', usetex=True)
             plt.rc('font', family='serif')
+        else:
+            plt.rc('text', usetex=False)
+            plt.rc('font', family='DejaVu Sans')
 
         if persistence_file != "":
             if dimension is None: