TST: tight_layout having negative width axes

jklymak · jklymak · commit 473071994ee0 · 2018-03-31T20:59:08.000-07:00
diff --git a/lib/matplotlib/tests/test_tightlayout.py b/lib/matplotlib/tests/test_tightlayout.py
@@ -272,3 +272,41 @@ def test_empty_layout():
 
     fig = plt.gcf()
     fig.tight_layout()
+
+
+def test_big_decorators_horizontal():
+    "Test that warning emited when xlabel too big"
+    fig, ax = plt.subplots(figsize=(3, 2))
+    ax.set_xlabel('a' * 100)
+    with warnings.catch_warnings(record=True) as w:
+        fig.tight_layout()
+        assert len(w) == 1
+
+
+def test_big_decorators_verticaltal():
+    "Test that warning emited when xlabel too big"
+    fig, ax = plt.subplots(figsize=(3, 2))
+    ax.set_ylabel('a' * 100)
+    with warnings.catch_warnings(record=True) as w:
+        fig.tight_layout()
+        assert len(w) == 1
+
+
+def test_big_decorators_horizontal():
+    "Test that warning emited when xlabel too big"
+    fig, axs = plt.subplots(1, 2, figsize=(3, 2))
+    axs[0].set_xlabel('a' * 30)
+    axs[1].set_xlabel('b' * 30)
+    with warnings.catch_warnings(record=True) as w:
+        fig.tight_layout()
+        assert len(w) == 1
+
+
+def test_big_decorators_vertical():
+    "Test that warning emited when xlabel too big"
+    fig, axs = plt.subplots(2, 1, figsize=(3, 2))
+    axs[0].set_ylabel('a' * 20)
+    axs[1].set_ylabel('b' * 20)
+    with warnings.catch_warnings(record=True) as w:
+        fig.tight_layout()
+        assert len(w) == 1
diff --git a/lib/matplotlib/tight_layout.py b/lib/matplotlib/tight_layout.py
@@ -176,6 +176,12 @@ def auto_adjust_subplotpars(
         margin_right = 0.4999
         warnings.warn('The left and right margins cannot be made large '
                       'enough to accomodate all axes decorations. ')
+    if margin_bottom + margin_top >= 1:
+        margin_bottom = 0.4999
+        margin_top = 0.4999
+        warnings.warn('The bottom and top margins cannot be made large '
+                      'enough to accomodate all axes decorations. ')
+
     kwargs = dict(left=margin_left,
                   right=1 - margin_right,
                   bottom=margin_bottom,
@@ -188,7 +194,7 @@ def auto_adjust_subplotpars(
             + hpad_inches / fig_width_inch)
         # axes widths:
         h_axes = (1 - margin_right - margin_left - hspace * (cols - 1)) / cols
-        if h_axes < 0.:
+        if h_axes < 0:
             warnings.warn('tight_layout cannot make axes width small enough '
                           'to accomodate all axes decorations')
             kwargs["wspace"] = 0.5
