Merge pull request #9285 from tacaswell/fix_fullymasked_image

anntzer · web-flow · commit b03e0b28386e · 2017-10-12T13:08:49.000-07:00
FIX: handle fully masked data
diff --git a/lib/matplotlib/image.py b/lib/matplotlib/image.py
@@ -368,10 +368,14 @@ def _make_image(self, A, in_bbox, out_bbox, clip_bbox, magnification=1.0,
                     scaled_dtype = A.dtype
                 else:
                     scaled_dtype = np.float32
-                # old versions of numpy do not work with `np.nammin`
-                # and `np.nanmax` as inputs
-                a_min = np.ma.min(A).astype(scaled_dtype)
-                a_max = np.ma.max(A).astype(scaled_dtype)
+
+                a_min = A.min()
+                if a_min is np.ma.masked:
+                    a_min, a_max = 0, 1  # all masked, so values don't matter
+                else:
+                    a_min = a_min.astype(scaled_dtype)
+                    a_max = A.max().astype(scaled_dtype)
+
                 # scale the input data to [.1, .9].  The Agg
                 # interpolators clip to [0, 1] internally, use a
                 # smaller input scale to identify which of the
diff --git a/lib/matplotlib/tests/test_image.py b/lib/matplotlib/tests/test_image.py
@@ -835,3 +835,13 @@ def test_imshow_deprecated_interd_warn():
         with warnings.catch_warnings(record=True) as warns:
             getattr(im, k)
         assert len(warns) == 1
+
+
+def test_full_invalid():
+    x = np.ones((10, 10))
+    x[:] = np.nan
+
+    f, ax = plt.subplots()
+    ax.imshow(x)
+
+    f.canvas.draw()
