2.0 Examples fixes. See matplotlib#6762

These are fixes for all issues found in axes_grid, color, and
event_handling sections on the examples page.

axis_grid/demo_colorbar_with_inset_locator.py - changed interpolation from the
default(previously bilinear now none) to 'bilinear' to match 1.5.1 example

axes_grid1/simple_axesgrid.py - set interpolation to bilinear

axisartist/demo_curvelinear_grid.py - Set linewidth=2.0 and grid zorder=0 so
the plotted lines actually visible

event_handling/keypress_demo.py - added usage instruction as axes title

event_handling/lasso_demo.py - added usage instruction as axes title

event_handling/looking_glass.py - added usage instruction as axes title

event_handling/resample.py - removed gtk and hardcoded wave file dependencies
and just created a sample signal within the script

event_handling/trifinder_event_demo.py - zip(l1,l2) call changed to
list(zip(l1,l2)) to be python3 compatible

event_handling/viewlims.py - The focus box that is supposed to appear in the
left axes when user zooms in the right axes wasn't visible. Set linewidth=1.0

Author: mlub

examples/axes_grid1/demo_colorbar_with_inset_locator.py

@@ -9,7 +9,7 @@
                     height="5%",  # height : 50%
                     loc=1)
 
-im1 = ax1.imshow([[1, 2], [2, 3]])
+im1 = ax1.imshow([[1, 2], [2, 3]], interpolation='bilinear')
 plt.colorbar(im1, cax=axins1, orientation="horizontal", ticks=[1, 2, 3])
 axins1.xaxis.set_ticks_position("bottom")
 
@@ -26,7 +26,7 @@
 # of the legend.  you may want to play with the borderpad value and
 # the bbox_to_anchor coordinate.
 
-im = ax2.imshow([[1, 2], [2, 3]])
+im = ax2.imshow([[1, 2], [2, 3]], interpolation='bilinear')
 plt.colorbar(im, cax=axins, ticks=[1, 2, 3])
 
 plt.draw()

examples/axes_grid1/simple_axesgrid.py

@@ -12,6 +12,6 @@
                  )
 
 for i in range(4):
-    grid[i].imshow(im)  # The AxesGrid object work as a list of axes.
+    grid[i].imshow(im, interpolation='bilinear')  # The AxesGrid object work as a list of axes.
 
 plt.show()

examples/axisartist/demo_curvelinear_grid.py

@@ -34,15 +34,15 @@ def inv_tr(x, y):
     fig.add_subplot(ax1)
 
     xx, yy = tr([3, 6], [5.0, 10.])
-    ax1.plot(xx, yy)
+    ax1.plot(xx, yy, linewidth=2.0)
 
     ax1.set_aspect(1.)
     ax1.set_xlim(0, 10.)
     ax1.set_ylim(0, 10.)
 
     ax1.axis["t"] = ax1.new_floating_axis(0, 3.)
     ax1.axis["t2"] = ax1.new_floating_axis(1, 7.)
-    ax1.grid(True)
+    ax1.grid(True, zorder=0)
 
 
 import mpl_toolkits.axisartist.angle_helper as angle_helper
@@ -107,13 +107,14 @@ def curvelinear_test2(fig):
     ax1.parasites.append(ax2)
     intp = cbook.simple_linear_interpolation
     ax2.plot(intp(np.array([0, 30]), 50),
-             intp(np.array([10., 10.]), 50))
+             intp(np.array([10., 10.]), 50),
+             linewidth=2.0)
 
     ax1.set_aspect(1.)
     ax1.set_xlim(-5, 12)
     ax1.set_ylim(-5, 10)
 
-    ax1.grid(True)
+    ax1.grid(True, zorder=0)
 
 if 1:
     fig = plt.figure(1, figsize=(7, 4))

examples/event_handling/keypress_demo.py

@@ -21,5 +21,5 @@ def press(event):
 
 ax.plot(np.random.rand(12), np.random.rand(12), 'go')
 xl = ax.set_xlabel('easy come, easy go')
-
+ax.set_title('Press a key')
 plt.show()

examples/event_handling/lasso_demo.py

@@ -77,8 +77,9 @@ def onpress(self, event):
 if __name__ == '__main__':
 
     data = [Datum(*xy) for xy in rand(100, 2)]
-
     ax = plt.axes(xlim=(0, 1), ylim=(0, 1), autoscale_on=False)
+    ax.set_title('Lasso points using left mouse button')
+
     lman = LassoManager(ax, data)
 
     plt.show()

examples/event_handling/looking_glass.py

@@ -10,7 +10,7 @@
 
 ax.plot(x, y, alpha=0.2)
 line, = ax.plot(x, y, alpha=1.0, clip_path=circ)
-
+ax.set_title("Left click and drag to move looking glass")
 
 class EventHandler(object):
     def __init__(self):

examples/event_handling/resample.py

@@ -1,26 +1,24 @@
 import numpy as np
 import matplotlib.pyplot as plt
-from scikits.audiolab import wavread
 
 
 # A class that will downsample the data and recompute when zoomed.
 class DataDisplayDownsampler(object):
     def __init__(self, xdata, ydata):
         self.origYData = ydata
         self.origXData = xdata
-        self.numpts = 3000
+        self.ratio = 5
         self.delta = xdata[-1] - xdata[0]
 
-    def resample(self, xstart, xend):
+    def downsample(self, xstart, xend):
         # Very simple downsampling that takes the points within the range
         # and picks every Nth point
         mask = (self.origXData > xstart) & (self.origXData < xend)
         xdata = self.origXData[mask]
-        ratio = int(xdata.size / self.numpts) + 1
-        xdata = xdata[::ratio]
+        xdata = xdata[::self.ratio]
 
         ydata = self.origYData[mask]
-        ydata = ydata[::ratio]
+        ydata = ydata[::self.ratio]
 
         return xdata, ydata
 
@@ -33,21 +31,21 @@ def update(self, ax):
             self.line.set_data(*self.downsample(xstart, xend))
             ax.figure.canvas.draw_idle()
 
-# Read data
-data = wavread('/usr/share/sounds/purple/receive.wav')[0]
-ydata = np.tile(data[:, 0], 100)
-xdata = np.arange(ydata.size)
+# Create a signal
+xdata = np.linspace(16,365,365-16)
+ydata = np.sin(2*np.pi*xdata/153) + np.cos(2*np.pi*xdata/127);
 
 d = DataDisplayDownsampler(xdata, ydata)
 
 fig, ax = plt.subplots()
 
 # Hook up the line
-xdata, ydata = d.downsample(xdata[0], xdata[-1])
-d.line, = ax.plot(xdata, ydata)
+d.line, = ax.plot(xdata, ydata,'o-')
 ax.set_autoscale_on(False)  # Otherwise, infinite loop
 
 # Connect for changing the view limits
 ax.callbacks.connect('xlim_changed', d.update)
 
 plt.show()
+
+

examples/event_handling/trifinder_event_demo.py

@@ -17,7 +17,7 @@ def update_polygon(tri):
         points = triangulation.triangles[tri]
     xs = triangulation.x[points]
     ys = triangulation.y[points]
-    polygon.set_xy(zip(xs, ys))
+    polygon.set_xy(list(zip(xs, ys)))
 
 
 def motion_notify(event):

examples/event_handling/viewlims.py

@@ -64,7 +64,7 @@ def ax_update(self, ax):
 ax1.imshow(Z, origin='lower', extent=(md.x.min(), md.x.max(), md.y.min(), md.y.max()))
 ax2.imshow(Z, origin='lower', extent=(md.x.min(), md.x.max(), md.y.min(), md.y.max()))
 
-rect = UpdatingRect([0, 0], 0, 0, facecolor='None', edgecolor='black')
+rect = UpdatingRect([0, 0], 0, 0, facecolor='None', edgecolor='black', linewidth=1.0)
 rect.set_bounds(*ax2.viewLim.bounds)
 ax1.add_patch(rect)
 
@@ -74,5 +74,6 @@ def ax_update(self, ax):
 
 ax2.callbacks.connect('xlim_changed', md.ax_update)
 ax2.callbacks.connect('ylim_changed', md.ax_update)
+ax2.set_title("Zoom here")
 
 plt.show()