fixed: compare_images for older numpy versions. added: backend_pdf allows numpy.float32 in pdfRepr

Michael Welter · mdboom · commit c39d9dc0932e · 2013-05-24T14:44:46.000-04:00
diff --git a/lib/matplotlib/testing/compare.py b/lib/matplotlib/testing/compare.py
@@ -306,6 +306,36 @@ def compare_images( expected, actual, tol, in_decorator=False ):
    expectedImage = expectedImage.astype(np.int16)
    actualImage = actualImage.astype(np.int16)
 
+   # compare the resulting image histogram functions
+   expected_version = version.LooseVersion("1.6")
+   found_version = version.LooseVersion(np.__version__)
+
+   # On Numpy 1.6, we can use bincount with minlength, which is much faster than
+   # using histogram
+   if found_version >= expected_version:
+      rms = 0
+
+      for i in xrange(0, 3):
+         h1p = expectedImage[:,:,i]
+         h2p = actualImage[:,:,i]
+
+         h1h = np.bincount(h1p.ravel(), minlength=256)
+         h2h = np.bincount(h2p.ravel(), minlength=256)
+
+         rms += np.sum(np.power((h1h-h2h), 2))
+   else:
+      rms = 0
+      ns = np.arange(257)
+
+      for i in xrange(0, 3):
+         h1p = expectedImage[:,:,i]
+         h2p = actualImage[:,:,i]
+
+         h1h = np.histogram(h1p, bins=ns)[0]
+         h2h = np.histogram(h2p, bins=ns)[0]
+
+         rms += np.sum(np.power((h1h-h2h), 2))
+
    rms = calculate_rms(expectedImage, actualImage)
 
    diff_image = make_test_filename(actual, 'failed-diff')
