Use rc() less often in examples/tutorials.

anntzer · anntzer · commit 52adc3fbbd9e · 2020-02-26T19:46:10.000+01:00
If a user learns rcParams.update / dict.update, they'll know how to
merge any dicts, whereas rc() is a matplotlib-specific API which is
hardly shorter (and needing star-unpacking in the case of
tutorials/text/usetex.py, which makes things worse overall).

Also it's often better to just pass the argument to the single
function call (`text(..., usetex=True)`, `imshow(..., origin="lower")`)
which avoids unnecessarily touching global state.
diff --git a/examples/misc/multipage_pdf.py b/examples/misc/multipage_pdf.py
@@ -26,8 +26,8 @@
     pdf.savefig()  # saves the current figure into a pdf page
     plt.close()
 
-    # if LaTeX is not installed or error caught, change to `usetex=False`
-    plt.rc('text', usetex=True)
+    # if LaTeX is not installed or error caught, change to `False`
+    plt.rcParams['text.usetex'] = True
     plt.figure(figsize=(8, 6))
     x = np.arange(0, 5, 0.1)
     plt.plot(x, np.sin(x), 'b-')
@@ -36,7 +36,7 @@
     pdf.savefig()
     plt.close()
 
-    plt.rc('text', usetex=False)
+    plt.rcParams['text.usetex'] = False
     fig = plt.figure(figsize=(4, 5))
     plt.plot(x, x ** 2, 'ko')
     plt.title('Page Three')
diff --git a/examples/text_labels_and_annotations/mathtext_asarray.py b/examples/text_labels_and_annotations/mathtext_asarray.py
@@ -8,8 +8,6 @@
 
 import matplotlib.mathtext as mathtext
 import matplotlib.pyplot as plt
-import matplotlib
-matplotlib.rc('image', origin='upper')
 
 parser = mathtext.MathTextParser("Bitmap")
 parser.to_png('test2.png',
diff --git a/examples/text_labels_and_annotations/usetex_fonteffects.py b/examples/text_labels_and_annotations/usetex_fonteffects.py
@@ -7,9 +7,7 @@
 are now supported in pdf usetex.
 """
 
-import matplotlib
 import matplotlib.pyplot as plt
-matplotlib.rc('text', usetex=True)
 
 
 def setfont(font):
@@ -22,7 +20,7 @@ def setfont(font):
                          ['Nimbus Roman No9 L ' + x for x in
                           ['', 'Italics (real italics for comparison)',
                            '(slanted)', '(condensed)', '(extended)']]):
-    plt.text(0, y, setfont(font) + text)
+    plt.text(0, y, setfont(font) + text, usetex=True)
 
 plt.ylim(-1, 5)
 plt.xlim(-0.2, 0.6)
diff --git a/examples/user_interfaces/embedding_in_wx3_sgskip.py b/examples/user_interfaces/embedding_in_wx3_sgskip.py
@@ -21,7 +21,6 @@
 Thanks to matplotlib and wx teams for creating such great software!
 """
 
-import matplotlib
 import matplotlib.cm as cm
 import matplotlib.cbook as cbook
 from matplotlib.backends.backend_wxagg import (
@@ -36,9 +35,6 @@
 ERR_TOL = 1e-5  # floating point slop for peak-detection
 
 
-matplotlib.rc('image', origin='lower')
-
-
 class PlotPanel(wx.Panel):
     def __init__(self, parent):
         wx.Panel.__init__(self, parent, -1)
@@ -64,7 +60,7 @@ def init_plot_data(self):
         y = np.arange(100.0) * 2 * np.pi / 50.0
         self.x, self.y = np.meshgrid(x, y)
         z = np.sin(self.x) + np.cos(self.y)
-        self.im = ax.imshow(z, cmap=cm.RdBu)
+        self.im = ax.imshow(z, cmap=cm.RdBu, origin='lower')
 
         zmax = np.max(z) - ERR_TOL
         ymax_i, xmax_i = np.nonzero(z >= zmax)
diff --git a/tutorials/text/usetex.py b/tutorials/text/usetex.py
@@ -45,11 +45,17 @@
 To use LaTeX and select Helvetica as the default font, without editing
 matplotlibrc use::
 
-  from matplotlib import rc
-  rc('font', **{'family': 'sans-serif', 'sans-serif': ['Helvetica']})
+  import matplotlib as mpl
+  plt.rcParams.update({
+      "text.usetex": True,
+      "font.family": "sans-serif",
+      "font.sans-serif": ["Helvetica"]})
   ## for Palatino and other serif fonts use:
-  # rc('font', **{'family': 'serif', 'serif': ['Palatino']})
-  rc('text', usetex=True)
+  plt.rcParams.update({
+      "text.usetex": True,
+      "font.family": "serif",
+      "font.serif": ["Palatino"],
+  })
 
 Here is the standard example,
 :file:`/gallery/text_labels_and_annotations/tex_demo`:
