MNT/DOC: remove all usage of Figure.clf from codebase

Author: tacaswell

doc/api/prev_api_changes/api_changes_3.0.0.rst

@@ -471,7 +471,7 @@ Hold machinery
 Setting or unsetting ``hold`` (:ref:`deprecated in version 2.0<v200_deprecate_hold>`) has now
 been completely removed. Matplotlib now always behaves as if ``hold=True``.
 To clear an axes you can manually use :meth:`~.axes.Axes.cla()`,
-or to clear an entire figure use :meth:`~.figure.Figure.clf()`.
+or to clear an entire figure use :meth:`~.figure.Figure.clear()`.
 
 
 Removal of deprecated backends

doc/users/prev_whats_new/changelog.rst

@@ -3139,7 +3139,7 @@ the `API changes <../../api/api_changes.html>`_.
     Fixed a bug in backend_qt4, reported on mpl-dev - DSD
 
 2007-03-26
-    Removed colorbar_classic from figure.py; fixed bug in Figure.clf() in which
+    Removed colorbar_classic from figure.py; fixed bug in Figure.clear() in which
     _axobservers was not getting cleared.  Modernization and cleanups. - EF
 
 2007-03-26

lib/matplotlib/pyplot.py

@@ -953,7 +953,7 @@ def close(fig=None):
 
 def clf():
     """Clear the current figure."""
-    gcf().clf()
+    gcf().clear()
 
 
 def draw():

lib/matplotlib/tests/test_usetex.py

@@ -74,7 +74,7 @@ def test_minus_no_descent(fontsize):
     heights = {}
     fig = plt.figure()
     for vals in [(1,), (-1,), (-1, 1)]:
-        fig.clf()
+        fig.clear()
         for x in vals:
             fig.text(.5, .5, f"${x}$", usetex=True)
         fig.canvas.draw()