matplotlib · efiring · Jan 13, 2017 · Jan 4, 2017
diff --git a/doc/_static/.gitignore b/doc/_static/.gitignore
@@ -0,0 +1,5 @@
+contour_frontpage.png
+histogram_frontpage.png
+membrane_frontpage.png
+surface3d_frontpage.png
+
diff --git a/doc/_static/contour_frontpage.png b/doc/_static/contour_frontpage.png
diff --git a/doc/_static/histogram_frontpage.png b/doc/_static/histogram_frontpage.png
diff --git a/doc/_static/membrane_frontpage.png b/doc/_static/membrane_frontpage.png
diff --git a/doc/_static/mpl.css b/doc/_static/mpl.css
@@ -738,8 +738,8 @@ div.responsive_screenshots {
     margin: auto;
 
     /* Do not go beyond 1:1 scale (and ensure a 1x4 tight layout) */
-    max-width: 648px;  /* at most 4 x 1:1 subfig width  */
-    max-height: 139px; /* at most 1 x 1:1 subfig height */
+    max-width: 640px;  /* at most 4 x 1:1 subfig width  */
+    max-height: 120px; /* at most 1 x 1:1 subfig height */
 }
 
 /* To avoid subfigure parts outside of the responsive_screenshots  */

diff --git a/doc/_static/surface3d_frontpage.png b/doc/_static/surface3d_frontpage.png
diff --git a/doc/make.py b/doc/make.py
@@ -1,4 +1,5 @@
 #!/usr/bin/env python
+"""Wrapper script for calling Sphinx. """
 
 from __future__ import print_function
 import glob
@@ -7,9 +8,12 @@
 import sys
 import re
 import argparse
+import subprocess
 import matplotlib
 
+
 def copy_if_out_of_date(original, derived):
+    """Copy file only if newer as target or if target does not exist. """
     if (not os.path.exists(derived) or
         os.stat(derived).st_mtime < os.stat(original).st_mtime):
         try:
@@ -22,7 +26,9 @@ def copy_if_out_of_date(original, derived):
             else:
                 raise
 
+
 def check_build():
+    """Create target build directories if necessary. """
     build_dirs = ['build', 'build/doctrees', 'build/html', 'build/latex',
                   'build/texinfo', '_static', '_templates']
     for d in build_dirs:
@@ -31,14 +37,58 @@ def check_build():
         except OSError:
             pass
 
+
 def doctest():
+    """Execute Sphinx 'doctest' target. """
     os.system('sphinx-build -b doctest -d build/doctrees . build/doctest')
 
+
 def linkcheck():
+    """Execute Sphinx 'linkcheck' target. """
     os.system('sphinx-build -b linkcheck -d build/doctrees . build/linkcheck')
 
+
+# For generating PNGs of the top row of index.html:
+FRONTPAGE_PY_PATH = "../examples/frontpage/"  # python scripts location
+FRONTPAGE_PNG_PATH = "_static/"  # png files location
+# png files and corresponding generation scripts:
+FRONTPAGE_PNGS = {"surface3d_frontpage.png": "plot_3D.py",
+                  "contour_frontpage.png":   "plot_contour.py",
+                  "histogram_frontpage.png": "plot_histogram.py",
+                  "membrane_frontpage.png":  "plot_membrane.py"}
+
+
+def generate_frontpage_pngs(only_if_needed=True):
+    """Executes the scripts for PNG generation of the top row of index.html.
+
+    If `only_if_needed` is `True`, then the PNG file is only generated, if it
+    doesn't exist or if the python file is newer.
+
+    Note that the element `div.responsive_screenshots` in the file
+    `_static/mpl.css` has the height and cumulative width of the used PNG files
+    as attributes. This ensures that the magnification of those PNGs is <= 1.
+    """
+    for fn_png, fn_py in FRONTPAGE_PNGS.items():
+        pn_png = os.path.join(FRONTPAGE_PNG_PATH, fn_png)  # get full paths
+        pn_py = os.path.join(FRONTPAGE_PY_PATH, fn_py)
+
+        # Read file modification times:
+        mtime_py = os.path.getmtime(pn_py)
+        mtime_png = (os.path.getmtime(pn_png) if os.path.exists(pn_png) else
+                     mtime_py - 1)  # set older time, if file doesn't exist
+
+        if only_if_needed and mtime_py <= mtime_png:
+            continue  # do nothing if png is newer
+
+        # Execute python as subprocess (preferred over os.system()):
+        subprocess.check_call(["python", pn_py])  # raises CalledProcessError()
+        os.rename(fn_png, pn_png)  # move file to _static/ directory
+
+
 def html(buildername='html'):
+    """Build Sphinx 'html' target. """
     check_build()
+    generate_frontpage_pngs()
 
     rc = '../lib/matplotlib/mpl-data/matplotlibrc'
     default_rc = os.path.join(matplotlib._get_data_path(), 'matplotlibrc')
@@ -62,20 +112,24 @@ def html(buildername='html'):
 
     shutil.copy('../CHANGELOG', 'build/%s/_static/CHANGELOG' % buildername)
 
+
 def htmlhelp():
+    """Build Sphinx 'htmlhelp' target. """
     html(buildername='htmlhelp')
     # remove scripts from index.html
     with open('build/htmlhelp/index.html', 'r+') as fh:
         content = fh.read()
         fh.seek(0)
         content = re.sub(r'<script>.*?</script>', '', content,
-                         flags=re.MULTILINE| re.DOTALL)
+                         flags=re.MULTILINE | re.DOTALL)
         fh.write(content)
         fh.truncate()
 
+
 def latex():
+    """Build Sphinx 'latex' target. """
     check_build()
-    #figs()
+    # figs()
     if sys.platform != 'win32':
         # LaTeX format.
         if os.system('sphinx-build -b latex -d build/doctrees . build/latex'):
@@ -92,9 +146,11 @@ def latex():
     else:
         print('latex build has not been tested on windows')
 
+
 def texinfo():
+    """Build Sphinx 'texinfo' target. """
     check_build()
-    #figs()
+    # figs()
     if sys.platform != 'win32':
         # Texinfo format.
         if os.system(
@@ -112,7 +168,9 @@ def texinfo():
     else:
         print('texinfo build has not been tested on windows')
 
+
 def clean():
+    """Remove generated files. """
     shutil.rmtree("build", ignore_errors=True)
     shutil.rmtree("examples", ignore_errors=True)
     for pattern in ['mpl_examples/api/*.png',
@@ -126,21 +184,27 @@ def clean():
         for filename in glob.glob(pattern):
             if os.path.exists(filename):
                 os.remove(filename)
+        for fn in FRONTPAGE_PNGS.keys():  # remove generated PNGs
+            pn = os.path.join(FRONTPAGE_PNG_PATH, fn)
+            if os.path.exists(pn):
+                os.remove(os.path.join(pn))
+
 
-def all():
-    #figs()
+def build_all():
+    """Build Sphinx 'html' and 'latex' target. """
+    # figs()
     html()
     latex()
 
 
 funcd = {
-    'html'     : html,
-    'htmlhelp' : htmlhelp,
-    'latex'    : latex,
-    'texinfo'  : texinfo,
-    'clean'    : clean,
-    'all'      : all,
-    'doctest'  : doctest,
+    'html':      html,
+    'htmlhelp':  htmlhelp,
+    'latex':     latex,
+    'texinfo':   texinfo,
+    'clean':     clean,
+    'all':       build_all,
+    'doctest':   doctest,
     'linkcheck': linkcheck,
     }
 
@@ -168,8 +232,8 @@ def all():
         # This is special processing that applies on platforms that don't deal
         # with git symlinks -- probably only MS windows.
         delete = False
-        with open(link, 'r') as content:
-            delete = target == content.read()
+        with open(link, 'r') as link_content:
+            delete = target == link_content.read()
         if delete:
             symlink_warnings.append('deleted:  doc/{0}'.format(link))
             os.unlink(link)
@@ -186,7 +250,7 @@ def all():
 if sys.platform == 'win32' and len(symlink_warnings) > 0:
     print('The following items related to symlinks will show up '
           'as spurious changes in your \'git status\':\n\t{0}'
-                    .format('\n\t'.join(symlink_warnings)))
+          .format('\n\t'.join(symlink_warnings)))
 
 parser = argparse.ArgumentParser(description='Build matplotlib docs')
 parser.add_argument("cmd", help=("Command to execute. Can be multiple. "

diff --git a/examples/frontpage/plot_3D.py b/examples/frontpage/plot_3D.py
@@ -24,7 +24,7 @@
 region = np.s_[5:50, 5:50]
 x, y, z = x[region], y[region], z[region]
 
-fig, ax = plt.subplots(subplot_kw=dict(projection='3d'), figsize=(1.62, 1.38))
+fig, ax = plt.subplots(subplot_kw=dict(projection='3d'))
 
 ls = LightSource(270, 45)
 # To use a custom hillshading mode, override the built-in shading and pass
@@ -35,4 +35,4 @@
 ax.set_xticks([])
 ax.set_yticks([])
 ax.set_zticks([])
-fig.savefig("surface3d_frontpage.png")
+fig.savefig("surface3d_frontpage.png", dpi=25)  # results in 160x120 px image
diff --git a/examples/frontpage/plot_contour.py b/examples/frontpage/plot_contour.py
@@ -23,12 +23,12 @@
 levels = np.linspace(-2.0, 1.601, 40)
 norm = cm.colors.Normalize(vmax=abs(Z).max(), vmin=-abs(Z).max())
 
-fig, ax = plt.subplots(figsize=(1.62, 1.38))
+fig, ax = plt.subplots()
 cset1 = ax.contourf(
     X, Y, Z, levels,
     norm=norm)
 ax.set_xlim(-3, 3)
 ax.set_ylim(-3, 3)
 ax.set_xticks([])
 ax.set_yticks([])
-fig.savefig("contour_frontpage.png")
+fig.savefig("contour_frontpage.png", dpi=25)  # results in 160x120 px image
diff --git a/examples/frontpage/plot_histogram.py b/examples/frontpage/plot_histogram.py
@@ -13,10 +13,10 @@
 random_state = np.random.RandomState(19680801)
 X = random_state.randn(10000)
 
-fig, ax = plt.subplots(figsize=(1.62, 1.38))
+fig, ax = plt.subplots()
 ax.hist(X, bins=25, normed=True)
 x = np.linspace(-5, 5, 1000)
 ax.plot(x, 1 / np.sqrt(2*np.pi) * np.exp(-(x**2)/2), linewidth=4)
 ax.set_xticks([])
 ax.set_yticks([])
-fig.savefig("histogram_frontpage.png")
+fig.savefig("histogram_frontpage.png", dpi=25)  # results in 160x120 px image
diff --git a/examples/frontpage/plot_membrane.py b/examples/frontpage/plot_membrane.py
@@ -16,10 +16,10 @@
 x = np.fromfile(datafile, np.float32)
 # 0.0005 is the sample interval
 
-fig, ax = plt.subplots(figsize=(1.62, 1.38))
+fig, ax = plt.subplots()
 ax.plot(x, linewidth=4)
 ax.set_xlim(5000, 6000)
 ax.set_ylim(-0.6, 0.1)
 ax.set_xticks([])
 ax.set_yticks([])
-fig.savefig("membrane_frontpage.png")
+fig.savefig("membrane_frontpage.png", dpi=25)  # results in 160x120 px image
diff --git a/examples/pie_and_polar_charts/pie_demo_features.py b/examples/pie_and_polar_charts/pie_demo_features.py
@@ -16,48 +16,40 @@
 rotated counter-clockwise by 90 degrees, and the frog slice starts on the
 positive y-axis.
 """
+import numpy as np
 import matplotlib.pyplot as plt
 
-
-# The slices will be ordered and plotted counter-clockwise.
+# Pie chart, where the slices will be ordered and plotted counter-clockwise:
 labels = 'Frogs', 'Hogs', 'Dogs', 'Logs'
 sizes = [15, 30, 45, 10]
 explode = (0, 0.1, 0, 0)  # only "explode" the 2nd slice (i.e. 'Hogs')
 
-plt.pie(sizes, explode=explode, labels=labels,
-        autopct='%1.1f%%', shadow=True, startangle=90)
-# Set aspect ratio to be equal so that pie is drawn as a circle.
-plt.axis('equal')
-
-fig = plt.figure()
-ax = fig.gca()
-import numpy as np
-
-# Fixing random state for reproducibility
-np.random.seed(19680801)
-
-
-ax.pie(np.random.random(4), explode=explode, labels=labels,
-       autopct='%1.1f%%', shadow=True, startangle=90,
-       radius=0.25, center=(0, 0), frame=True)
-ax.pie(np.random.random(4), explode=explode, labels=labels,
-       autopct='%1.1f%%', shadow=True, startangle=90,
-       radius=0.25, center=(1, 1), frame=True)
-ax.pie(np.random.random(4), explode=explode, labels=labels,
-       autopct='%1.1f%%', shadow=True, startangle=90,
-       radius=0.25, center=(0, 1), frame=True)
-ax.pie(np.random.random(4), explode=explode, labels=labels,
-       autopct='%1.1f%%', shadow=True, startangle=90,
-       radius=0.25, center=(1, 0), frame=True)
-
-ax.set_xticks([0, 1])
-ax.set_yticks([0, 1])
-ax.set_xticklabels(["Sunny", "Cloudy"])
-ax.set_yticklabels(["Dry", "Rainy"])
-ax.set_xlim((-0.5, 1.5))
-ax.set_ylim((-0.5, 1.5))
-
-# Set aspect ratio to be equal so that pie is drawn as a circle.
-ax.set_aspect('equal')
+fg1, ax1 = plt.subplots()
+ax1.pie(sizes, explode=explode, labels=labels, autopct='%1.1f%%',
+        shadow=True, startangle=90)
+ax1.axis('equal')  # Equal aspect ratio ensures that pie is drawn as a circle.
+
+
+# Plot four Pie charts in a 2x2 grid:
+pie_data = [np.roll(sizes, i) for i in range(4)]  # generate some data
+pie_centerpos = [(0, 0), (0, 1), (1, 0), (1, 1)]  # the grid positions
+
+fg2, ax2 = plt.subplots()
+for data, cpos in zip(pie_data, pie_centerpos):
+    _, txts = ax2.pie(data, explode=explode, shadow=True, startangle=90,
+                      radius=0.35, center=cpos, frame=True, labeldistance=.7)
+    # Make texts include number and labels:
+    for t, l, d in zip(txts, labels, data):
+        t.set_text("%s\n %.1f%%" % (l, d))
+        t.set_horizontalalignment("center")
+        t.set_fontsize(8)
+
+ax2.set_xticks([0, 1])
+ax2.set_yticks([0, 1])
+ax2.set_xticklabels(["Sunny", "Cloudy"])
+ax2.set_yticklabels(["Dry", "Rainy"])
+ax2.set_xlim((-0.5, 1.5))
+ax2.set_ylim((-0.5, 1.5))
+ax2.set_aspect('equal')  # Equal aspect ratio ensures that the pie is a circle.
 
 plt.show()
diff --git a/examples/pylab_examples/polar_demo.py b/examples/pylab_examples/polar_demo.py
@@ -5,12 +5,14 @@
 import matplotlib.pyplot as plt
 
 
-r = np.arange(0, 3.0, 0.01)
+r = np.arange(0, 2, 0.01)
 theta = 2 * np.pi * r
 
 ax = plt.subplot(111, projection='polar')
 ax.plot(theta, r)
-ax.set_rmax(2.0)
+ax.set_rmax(2)
+ax.set_rticks([0.5, 1, 1.5, 2])  # less radial ticks
+ax.set_rlabel_position(-22.5)  # get radial labels away from plotted line
 ax.grid(True)
 
 ax.set_title("A line plot on a polar axis", va='bottom')