Merge pull request matplotlib#2372 from neggert/hist_endline_fix

Fix step histogram endline

Author: dmcdougall

lib/matplotlib/axes.py

@@ -8457,11 +8457,11 @@ def hist(self, x, bins=10, range=None, normed=False, weights=None,
             xvals, yvals = [], []
             for m in n:
                 # starting point for drawing polygon
-                y[0] = y[-1]
+                y[0] = y[1]
                 # top of the previous polygon becomes the bottom
                 y[2*len(bins)-1:] = y[1:2*len(bins)-1][::-1]
                 # set the top of this polygon
-                y[1:2*len(bins)-1:2], y[2:2*len(bins):2] = m, m
+                y[1:2*len(bins)-1:2], y[2:2*len(bins)-1:2] = m, m
                 if log:
                     y[y < minimum] = minimum
                 if orientation == 'horizontal':
@@ -8481,7 +8481,7 @@ def hist(self, x, bins=10, range=None, normed=False, weights=None,
                         facecolor=c))
             else:
                 for x, y, c in reversed(zip(xvals, yvals, color)):
-                    split = int(len(x) / 2) + 1
+                    split = 2 * len(bins)
                     patches.append(self.fill(
                         x[:split], y[:split],
                         closed=False, edgecolor=c,

lib/matplotlib/tests/baseline_images/test_axes/hist_step.png

@@ -1062,6 +1062,17 @@ def test_hist_offset():
     ax.hist(d2, bottom=15)
 
 
+@image_comparison(baseline_images=['hist_step'], extensions=['png'], remove_text=True)
+def test_hist_step():
+    # make some data
+    d1 = np.linspace(1, 3, 20)
+    fig = plt.figure()
+    ax = fig.add_subplot(111)
+    ax.hist( d1, histtype="step")
+    ax.set_ylim(0, 10)
+    ax.set_xlim(-1, 5)
+
+
 @image_comparison(baseline_images=['hist_stacked_weights'])
 def test_hist_stacked_weighted():
     # make some data