From: W. Trevor King <wking@tremily.us>
Date: Fri, 30 Nov 2012 19:25:59 +0000 (-0800)
Subject: plot_image.py: prefer matplotlib.pyplot over pylab
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=9f4dc1d8982edbc7bff42fe53746f327e91d3ec1;p=assignment-template.git

plot_image.py: prefer matplotlib.pyplot over pylab

pylab bundles both the pyplot and numpy namespaces, so a careful
program will avoid it and use the underlying modules directly.
---

diff --git a/src/plot_image/plot_image.py b/src/plot_image/plot_image.py
index 7766530..ef8f057 100755
--- a/src/plot_image/plot_image.py
+++ b/src/plot_image/plot_image.py
@@ -42,7 +42,7 @@ For usage info, run::
     ./plot_image.py --help
 
 When run with interactive output (i.e. no `-o ...` option), the
-interactive figure is displayed using `pylab.show`, which means that
+interactive figure is displayed using `pyplot.show`, which means that
 you'll have to kill `plot_image.py` using ^C or similar [1]_.
 
 For other ideas, see the Matplotlib website [2]_.
@@ -55,13 +55,15 @@ import optparse
 import sys
 
 import matplotlib
+import matplotlib.cm
 import matplotlib.image
 import numpy
 
 # Depending on your Matplotlib configuration, you may need to adjust
-# your backend.  Do this before importing pylab or matplotlib.backends.
+# your backend.  Do this before importing pylab, matplotlib.pyplot, or
+# matplotlib.backends.
 #matplotlib.use('Agg')     # select backend that doesn't require X Windows
-#matplotlib.use('GTKAgg')  # select backend that supports pylab.show()
+#matplotlib.use('GTKAgg')  # select backend that supports pyplot.show()
 
 # Alternatively, you can configure the backend using
 # ~/.matplotlib/matplotlibrc:
@@ -69,7 +71,7 @@ import numpy
 #   backend : Agg
 #   #backend : GTKAgg
 
-import pylab
+import matplotlib.pyplot
 
 
 _DOC = __doc__
@@ -93,7 +95,7 @@ def read_data_1d(stream, nx, ny):
     array([[ 0.,  1.,  2.,  3.,  4.],
            [ 5.,  6.,  7.,  8.,  9.]])
     """
-    X,Y = pylab.meshgrid(range(nx+1), range(ny+1))
+    X,Y = numpy.meshgrid(range(nx+1), range(ny+1))
     Z = numpy.loadtxt(stream)
     assert Z.size == nx*ny, 'Z.size = %d != %d = %dx%d' % (
         Z.size, nx*ny, nx, ny)
@@ -138,14 +140,14 @@ def read_data_3d(stream):
     dy = Ys[-1] - Ys[-2]
     Xs = numpy.append(Xs, Xs[-1] + dx)
     Ys = numpy.append(Ys, Ys[-1] + dy)
-    X,Y = pylab.meshgrid(Xs, Ys)
+    X,Y = numpy.meshgrid(Xs, Ys)
     return (X,Y,Z)
 
 def plot(X, Y, Z, full=False, title=None, contours=None, interpolation=None,
          cmap=None):
     """Plot Z over the mesh X, Y.
 
-    >>> X, Y = pylab.meshgrid(range(6), range(2))
+    >>> X, Y = numpy.meshgrid(range(6), range(2))
     >>> Z = X[:-1,:-1]**2 + Y[:-1,:-1]
     >>> plot(X, Y, Z)  # doctest: +ELLIPSIS
     <matplotlib.figure.Figure object at 0x...>
@@ -155,7 +157,7 @@ def plot(X, Y, Z, full=False, title=None, contours=None, interpolation=None,
     Y_min = Y[0,0]
     Y_max = Y[-1,-1]
 
-    fig = pylab.figure()
+    fig = matplotlib.pyplot.figure()
     if full:
         axes = fig.add_axes([0, 0, 1, 1])
     else:
@@ -252,7 +254,7 @@ def main(argv=None):
     p.add_option('--interpolation', dest='interpolation', default='nearest',
                  help=('Interpolation scheme (for false color images) from %s '
                        '(%%default)') % ', '.join(interpolations))
-    maps=[m for m in pylab.cm.datad if not m.endswith("_r")]
+    maps=[m for m in matplotlib.cm.datad if not m.endswith("_r")]
     maps.sort()
     p.add_option('-m', '--color-map', dest='cmap', default='jet',
                  help='Select color map from %s (%%default)' % ', '.join(maps))
@@ -264,7 +266,7 @@ def main(argv=None):
 
     nx,ny = [int(x) for x in options.size.split(',')]
     try:
-        cmap = getattr(pylab.cm, options.cmap)
+        cmap = getattr(matplotlib.cm, options.cmap)
     except AttributeError:
         raise Exception('no color map named %s in %s'
                         % (options.cmap, ', '.join(maps)))
@@ -305,7 +307,7 @@ def main(argv=None):
     if options.output:
         fig.savefig(options.output)
     else:
-        pylab.show()
+        matplotlib.pyplot.show()
 
 
 if __name__ == '__main__':