matplotlib · NelleV · Jul 15, 2017 · Mar 7, 2017 · Mar 7, 2017 · Mar 10, 2017
diff --git a/examples/axisartist/demo_axisline_style.py b/examples/axisartist/demo_axisline_style.py
@@ -1,8 +1,9 @@
 """
-===================
-Demo Axisline Style
-===================
+================
+Axis line styles
+================
 
+This example shows some configurations for axis style.
 """
 
 from mpl_toolkits.axisartist.axislines import SubplotZero
@@ -15,10 +16,14 @@
     fig.add_subplot(ax)
 
     for direction in ["xzero", "yzero"]:
+        # adds arrows at the ends of each axis
         ax.axis[direction].set_axisline_style("-|>")
+
+        # adds X and Y-axis from the origin
         ax.axis[direction].set_visible(True)
 
     for direction in ["left", "right", "bottom", "top"]:
+        # hides borders
         ax.axis[direction].set_visible(False)
 
     x = np.linspace(-0.5, 1., 100)

diff --git a/examples/event_handling/poly_editor.py b/examples/event_handling/poly_editor.py
@@ -4,8 +4,7 @@
 ===========
 
 This is an example to show how to build cross-GUI applications using
-matplotlib event handling to interact with objects on the canvas
-
+Matplotlib event handling to interact with objects on the canvas.
 """
 import numpy as np
 from matplotlib.lines import Line2D
@@ -34,17 +33,19 @@ class PolygonInteractor(object):
 
     def __init__(self, ax, poly):
         if poly.figure is None:
-            raise RuntimeError('You must first add the polygon to a figure or canvas before defining the interactor')
+            raise RuntimeError('You must first add the polygon to a figure '
+                               'or canvas before defining the interactor')
         self.ax = ax
         canvas = poly.figure.canvas
         self.poly = poly
 
         x, y = zip(*self.poly.xy)
-        self.line = Line2D(x, y, marker='o', markerfacecolor='r', animated=True)
+        self.line = Line2D(x, y,
+                           marker='o', markerfacecolor='r',
+                           animated=True)
         self.ax.add_line(self.line)
-        #self._update_line(poly)
 
-        cid = self.poly.add_callback(self.poly_changed)
+        self.cid = self.poly.add_callback(self.poly_changed)
         self._ind = None  # the active vert
 
         canvas.mpl_connect('draw_event', self.draw_callback)
@@ -113,7 +114,9 @@ def key_press_callback(self, event):
         elif event.key == 'd':
             ind = self.get_ind_under_point(event)
             if ind is not None:
-                self.poly.xy = [tup for i, tup in enumerate(self.poly.xy) if i != ind]
+                self.poly.xy = [tup
+                                for i, tup in enumerate(self.poly.xy)
+                                if i != ind]
                 self.line.set_data(zip(*self.poly.xy))
         elif event.key == 'i':
             xys = self.poly.get_transform().transform(self.poly.xy)
@@ -173,7 +176,6 @@ def motion_notify_callback(self, event):
     ax.add_patch(poly)
     p = PolygonInteractor(ax, poly)
 
-    #ax.add_line(p.line)
     ax.set_title('Click and drag a point to move it')
     ax.set_xlim((-2, 2))
     ax.set_ylim((-2, 2))

diff --git a/examples/event_handling/resample.py b/examples/event_handling/resample.py
@@ -1,9 +1,13 @@
 """
-========
-Resample
-========
+===============
+Resampling Data
+===============
 
+Downsampling lowers the sample rate or sample size of a signal. In
+this tutorial, the signal is downsampled when the plot is adjusted
+through dragging and zooming.
 """
+
 import numpy as np
 import matplotlib.pyplot as plt
 
@@ -13,18 +17,28 @@ class DataDisplayDownsampler(object):
     def __init__(self, xdata, ydata):
         self.origYData = ydata
         self.origXData = xdata
-        self.ratio = 5
+        self.max_points = 50
         self.delta = xdata[-1] - xdata[0]
 
     def downsample(self, xstart, xend):
-        # Very simple downsampling that takes the points within the range
-        # and picks every Nth point
+        # get the points in the view range
         mask = (self.origXData > xstart) & (self.origXData < xend)
-        xdata = self.origXData[mask]
-        xdata = xdata[::self.ratio]
+        # dilate the mask by one to catch the points just outside
+        # of the view range to not truncate the line
+        mask = np.convolve([1, 1], mask, mode='same').astype(bool)
+        # sort out how many points to drop
+        ratio = max(np.sum(mask) // self.max_points, 1)

+        # mask data
+        xdata = self.origXData[mask]
         ydata = self.origYData[mask]
-        ydata = ydata[::self.ratio]
+
+        # downsample data
+        xdata = xdata[::ratio]
+        ydata = ydata[::ratio]
+
+        print("using {} of {} visible points".format(
+            len(ydata), np.sum(mask)))
 
         return xdata, ydata
 
@@ -37,8 +51,9 @@ def update(self, ax):
             self.line.set_data(*self.downsample(xstart, xend))
             ax.figure.canvas.draw_idle()
 
+
 # Create a signal
-xdata = np.linspace(16, 365, 365-16)
+xdata = np.linspace(16, 365, (365-16)*4)
 ydata = np.sin(2*np.pi*xdata/153) + np.cos(2*np.pi*xdata/127)
 
 d = DataDisplayDownsampler(xdata, ydata)
@@ -51,5 +66,5 @@ def update(self, ax):
 
 # Connect for changing the view limits
 ax.callbacks.connect('xlim_changed', d.update)
-
+ax.set_xlim(16, 365)
 plt.show()
diff --git a/examples/mplot3d/lines3d.py b/examples/mplot3d/lines3d.py
@@ -1,9 +1,9 @@
 '''
-===================
-3D parametric curve
-===================
+================
+Parametric Curve
+================
 
-Demonstrating plotting a parametric curve in 3D.
+This example demonstrates plotting a parametric curve in 3D.
 '''
 
 import matplotlib as mpl

diff --git a/examples/mplot3d/lorenz_attractor.py b/examples/mplot3d/lorenz_attractor.py
@@ -1,11 +1,12 @@
 '''
-====================
-The Lorenz Attractor
-====================
+================
+Lorenz Attractor
+================
 
-Plot of the Lorenz Attractor based on Edward Lorenz's 1963 "Deterministic
-Nonperiodic Flow" publication.
-    http://journals.ametsoc.org/doi/abs/10.1175/1520-0469%281963%29020%3C0130%3ADNF%3E2.0.CO%3B2
+This is an example of plotting Edward Lorenz's 1963 `"Deterministic
+Nonperiodic Flow"
+<http://journals.ametsoc.org/doi/abs/10.1175/1520-0469%281963%29020%3C0130%3ADNF%3E2.0.CO%3B2>`_
+in a 3-dimensional space using mplot3d.
 
 Note: Because this is a simple non-linear ODE, it would be more easily
       done using SciPy's ode solver, but this approach depends only

diff --git a/examples/mplot3d/mixed_subplots.py b/examples/mplot3d/mixed_subplots.py
@@ -1,11 +1,10 @@
 """
-==================
-2D and 3D subplots
-==================
+=================================
+2D and 3D *Axes* in same *Figure*
+=================================
 
-Demonstrate the mixing of 2d and 3d subplots.
+This example shows a how to plot a 2D and 3D plot on the same figure.
 """
-
 from mpl_toolkits.mplot3d import Axes3D
 import matplotlib.pyplot as plt
 import numpy as np

diff --git a/examples/mplot3d/offset.py b/examples/mplot3d/offset.py
@@ -1,7 +1,7 @@
    '''
-===================
-Offset text display
-===================
+=========================
+Automatic Text Offsetting
+=========================
 
 This example demonstrates mplot3d's offset text display.
 As one rotates the 3D figure, the offsets should remain oriented the

diff --git a/examples/pylab_examples/bar_stacked.py b/examples/pylab_examples/bar_stacked.py
@@ -1,10 +1,15 @@
 """
-===========
-Bar Stacked
-===========
+=================
+Stacked Bar Graph
+=================
+
+This is an example of creating a stacked bar plot with error bars
+using `~matplotlib.pyplot.bar`.  Note the parameters *yerr* used for
+error bars, and *bottom* to stack the women's bars on top of the men's
+bars.
 
-A stacked bar plot with errorbars.
 """
+
 import numpy as np
 import matplotlib.pyplot as plt
 

diff --git a/examples/pylab_examples/dolphin.py b/examples/pylab_examples/dolphin.py
@@ -1,9 +1,13 @@
 """
-=======
-Dolphin
-=======
+========
+Dolphins
+========
+
+This example shows how to draw, and manipulate shapes given vertices
+and nodes using the `Patches`, `Path` and `Transforms` classes.
 
 """
+
 import matplotlib.cm as cm
 import matplotlib.pyplot as plt
 from matplotlib.patches import Circle, PathPatch

diff --git a/examples/pylab_examples/fill_between_demo.py b/examples/pylab_examples/fill_between_demo.py
@@ -1,9 +1,12 @@
 """
-=================
-Fill Between Demo
-=================
+==============================
+Filling the area between lines
+==============================
 
+This example shows how to use `fill_between` to color between lines based on
+user-defined logic.
 """
+
 import matplotlib.pyplot as plt
 import numpy as np
 

diff --git a/examples/pylab_examples/geo_demo.py b/examples/pylab_examples/geo_demo.py
@@ -1,9 +1,14 @@
 """
-========
-Geo Demo
-========
+======================
+Geographic Projections
+======================
+
+This shows 4 possible projections using subplot.  Matplotlib also
+supports `Basemaps Toolkit <https://matplotlib.org/basemap>`_ and
+`Cartopy <http://scitools.org.uk/cartopy>`_ for geographic projections.
 
 """
+
 import matplotlib.pyplot as plt
 
 plt.figure()

diff --git a/examples/pylab_examples/log_test.py b/examples/pylab_examples/log_test.py
@@ -1,9 +1,12 @@
 """
 ========
-Log Test
+Log Axis
 ========
 
+This is an example of assigning a log-scale for the x-axis using
+`semilogx`.
 """
+
 import matplotlib.pyplot as plt
 import numpy as np
 

diff --git a/examples/pylab_examples/mri_demo.py b/examples/pylab_examples/mri_demo.py
@@ -1,11 +1,13 @@
 """
-========
-MRI Demo
-========
+===
+MRI
+===
 
-Displays an MRI image.
-"""
 
+This example illustrates how to read an image (of an MRI) into a NumPy
+array, and display it in greyscale using `imshow`.
+
+"""
 
 import matplotlib.pyplot as plt
 import matplotlib.cbook as cbook