BUG : raise exception in subplot if num out of range

tacaswell · tacaswell · commit 10bc45ea8baf · 2014-07-06T17:47:32.000-04:00
if subplot(rows, cols, num) is called with num not in 0 < num <= rows * cols raise a ValueError close #3166
diff --git a/lib/matplotlib/axes/_subplots.py b/lib/matplotlib/axes/_subplots.py
@@ -55,6 +55,10 @@ def __init__(self, fig, *args, **kwargs):
                 num = [int(n) for n in num]
                 self._subplotspec = GridSpec(rows, cols)[num[0] - 1:num[1]]
             else:
+                if num == 0 or num > rows*cols:
+                    raise ValueError(
+                        "num must be 0 < num <= {maxn}, not {num}".format(
+                            maxn=rows*cols, num=num))
                 self._subplotspec = GridSpec(rows, cols)[int(num) - 1]
                 # num - 1 for converting from MATLAB to python indexing
         else:
diff --git a/lib/matplotlib/tests/test_subplots.py b/lib/matplotlib/tests/test_subplots.py
@@ -6,7 +6,7 @@
 
 import numpy
 import matplotlib.pyplot as plt
-from matplotlib.testing.decorators import image_comparison
+from matplotlib.testing.decorators import image_comparison, cleanup
 
 from nose.tools import assert_raises
 
@@ -105,19 +105,22 @@ def test_exceptions():
     # TODO should this test more options?
     assert_raises(ValueError, plt.subplots, 2, 2, sharex='blah')
     assert_raises(ValueError, plt.subplots, 2, 2, sharey='blah')
+    assert_raises(ValueError, plt.subplots, 2, 2, 0)
+    assert_raises(ValueError, plt.subplots, 2, 2, 5)
 
 
 @image_comparison(baseline_images=['subplots_offset_text'], remove_text=False)
 def test_subplots_offsettext():
-    x = numpy.arange(0,1e10,1e9)
-    y = numpy.arange(0,100,10)+1e4
-    fig,axes = plt.subplots(2,2, sharex = 'col', sharey = 'all')
-    axes[0,0].plot(x,x)
-    axes[1,0].plot(x,x)
-    axes[0,1].plot(y,x)
-    axes[1,1].plot(y,x)
+    x = numpy.arange(0, 1e10, 1e9)
+    y = numpy.arange(0, 100, 10)+1e4
+    fig, axes = plt.subplots(2, 2, sharex='col', sharey='all')
+    axes[0, 0].plot(x, x)
+    axes[1, 0].plot(x, x)
+    axes[0, 1].plot(y, x)
+    axes[1, 1].plot(y, x)
 
 
+@cleanup
 def test_subplots():
     # things to test
     # - are axes actually shared?
