test for shared log axes

efiring · efiring · commit 9ca7b19e5d18 · 2016-12-10T18:47:47.000-10:00
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -176,6 +176,25 @@ def test_autoscale_tight():
     assert_allclose(ax.get_xlim(), (-0.15, 3.15))
     assert_allclose(ax.get_ylim(), (1.0, 4.0))
 
+
+@cleanup(style='default')
+def test_autoscale_log_shared():
+    # related to github #7587
+    # array starts at zero to trigger _minpos handling
+    x = np.arange(100, dtype=float)
+    fig, (ax1, ax2) = plt.subplots(2, 1, sharex=True)
+    ax1.loglog(x, x)
+    ax2.semilogx(x, x)
+    ax1.autoscale(tight=True)
+    ax2.autoscale(tight=True)
+    plt.draw()
+    lims = (x[1], x[-1])
+    assert_allclose(ax1.get_xlim(), lims)
+    assert_allclose(ax1.get_ylim(), lims)
+    assert_allclose(ax2.get_xlim(), lims)
+    assert_allclose(ax2.get_ylim(), (x[0], x[-1]))
+
+
 @cleanup(style='default')
 def test_use_sticky_edges():
     fig, ax = plt.subplots()
diff --git a/lib/matplotlib/ticker.py b/lib/matplotlib/ticker.py
@@ -2305,11 +2305,11 @@ def nonsingular(self, vmin, vmax):
         # so for now we use 1 - minpos as a substitute.
 
         if vmin <= 0:
-            vmin = max(minpos, vmin)
-        if vmax >= 0:
-            vmax = min(1 - minpos, vmax)
+            vmin = minpos
+        if vmax >= 1:
+            vmax = 1 - minpos
         if vmin == vmax:
-            return 0.1 * vmin, 10 * vmin
+            return 0.1 * vmin, 1 - 0.1 * vmin
 
         return vmin, vmax
 
