pylab to plt and np

Author: domspad

examples/pylab_examples/contour_image.py

@@ -8,32 +8,34 @@
 desired.  In particular, note the usage of the "origin" and "extent"
 keyword arguments to imshow and contour.
 '''
-from pylab import *
+import matplotlib.pyplot as plt
+import numpy as np
+from matplotlib import mlab, cm
 
 # Default delta is large because that makes it fast, and it illustrates
 # the correct registration between image and contours.
 delta = 0.5
 
 extent = (-3, 4, -4, 3)
 
-x = arange(-3.0, 4.001, delta)
-y = arange(-4.0, 3.001, delta)
-X, Y = meshgrid(x, y)
-Z1 = bivariate_normal(X, Y, 1.0, 1.0, 0.0, 0.0)
-Z2 = bivariate_normal(X, Y, 1.5, 0.5, 1, 1)
+x = np.arange(-3.0, 4.001, delta)
+y = np.arange(-4.0, 3.001, delta)
+X, Y = np.meshgrid(x, y)
+Z1 = mlab.bivariate_normal(X, Y, 1.0, 1.0, 0.0, 0.0)
+Z2 = mlab.bivariate_normal(X, Y, 1.5, 0.5, 1, 1)
 Z = (Z1 - Z2) * 10
 
-levels = arange(-2.0, 1.601, 0.4)  # Boost the upper limit to avoid truncation errors.
+levels = np.arange(-2.0, 1.601, 0.4)  # Boost the upper limit to avoid truncation errors.
 
 norm = cm.colors.Normalize(vmax=abs(Z).max(), vmin=-abs(Z).max())
 cmap = cm.PRGn
 
-figure()
+plt.figure()
 
 
-subplot(2, 2, 1)
+plt.subplot(2, 2, 1)
 
-cset1 = contourf(X, Y, Z, levels,
+cset1 = plt.contourf(X, Y, Z, levels,
                  cmap=cm.get_cmap(cmap, len(levels) - 1),
                  norm=norm,
                  )
@@ -45,7 +47,7 @@
 # contour separately; don't try to change the edgecolor or edgewidth
 # of the polygons in the collections returned by contourf.
 # Use levels output from previous call to guarantee they are the same.
-cset2 = contour(X, Y, Z, cset1.levels,
+cset2 = plt.contour(X, Y, Z, cset1.levels,
                 colors='k',
                 hold='on')
 # We don't really need dashed contour lines to indicate negative
@@ -57,49 +59,49 @@
 # to set up an array of colors and linewidths.
 # We are making a thick green line as a zero contour.
 # Specify the zero level as a tuple with only 0 in it.
-cset3 = contour(X, Y, Z, (0,),
+cset3 = plt.contour(X, Y, Z, (0,),
                 colors='g',
                 linewidths=2,
                 hold='on')
-title('Filled contours')
-colorbar(cset1)
+plt.title('Filled contours')
+plt.colorbar(cset1)
 #hot()
 
 
-subplot(2, 2, 2)
+plt.subplot(2, 2, 2)
 
-imshow(Z, extent=extent, cmap=cmap, norm=norm)
-v = axis()
-contour(Z, levels, hold='on', colors='k',
+plt.imshow(Z, extent=extent, cmap=cmap, norm=norm)
+v = plt.axis()
+plt.contour(Z, levels, hold='on', colors='k',
         origin='upper', extent=extent)
-axis(v)
-title("Image, origin 'upper'")
+plt.axis(v)
+plt.title("Image, origin 'upper'")
 
-subplot(2, 2, 3)
+plt.subplot(2, 2, 3)
 
-imshow(Z, origin='lower', extent=extent, cmap=cmap, norm=norm)
-v = axis()
-contour(Z, levels, hold='on', colors='k',
+plt.imshow(Z, origin='lower', extent=extent, cmap=cmap, norm=norm)
+v = plt.axis()
+plt.contour(Z, levels, hold='on', colors='k',
         origin='lower', extent=extent)
-axis(v)
-title("Image, origin 'lower'")
+plt.axis(v)
+plt.title("Image, origin 'lower'")
 
-subplot(2, 2, 4)
+plt.subplot(2, 2, 4)
 
 # We will use the interpolation "nearest" here to show the actual
 # image pixels.
 # Note that the contour lines don't extend to the edge of the box.
 # This is intentional. The Z values are defined at the center of each
 # image pixel (each color block on the following subplot), so the
 # domain that is contoured does not extend beyond these pixel centers.
-im = imshow(Z, interpolation='nearest', extent=extent, cmap=cmap, norm=norm)
-v = axis()
-contour(Z, levels, hold='on', colors='k',
+im = plt.imshow(Z, interpolation='nearest', extent=extent, cmap=cmap, norm=norm)
+v = plt.axis()
+plt.contour(Z, levels, hold='on', colors='k',
         origin='image', extent=extent)
-axis(v)
-ylim = get(gca(), 'ylim')
-setp(gca(), ylim=ylim[::-1])
-title("Image, origin from rc, reversed y-axis")
-colorbar(im)
+plt.axis(v)
+ylim = plt.get(plt.gca(), 'ylim')
+plt.setp(plt.gca(), ylim=ylim[::-1])
+plt.title("Image, origin from rc, reversed y-axis")
+plt.colorbar(im)
 
-show()
+plt.show()