ENH : add flag to box_plot and bxp to manage (or not) xticks

Closes matplotlib#2921
 - added test for managa_xtick option to boxplot
 - added CHANGELOG and whats_new.rst entry for manage_xticks

CHANGELOG

@@ -1,6 +1,10 @@
 2014-03-27 Added tests for pie ccw parameter. Removed pdf and svg images
            from tests for pie linewidth parameter.
 
+2014-03-24 Added bool kwarg (manage_xticks) to boxplot to enable/disable
+	   the managemnet of the xlimits and ticks when making a boxplot.
+	   Default in True which maintains current behavior by default.
+
 2014-03-22 Added the keyword arguments wedgeprops and textprops to pie.
            Users can control the wedge and text properties of the pie
            in more detail, if they choose.

doc/users/whats_new.rst

@@ -56,6 +56,8 @@ kwargs. See the examples:
 :ref:`~examples/statistics/boxplot_demo.py` and
 :ref:`~examples/statistics/bxp_demo.py`
 
+Added a bool kwarg, `manage_xticks`, which if False disables the management
+of the xtick and xlim by `boxplot`.
 
 Support for datetime axes in 2d plots
 `````````````````````````````````````

lib/matplotlib/axes/_axes.py

@@ -2875,7 +2875,8 @@ def boxplot(self, x, notch=False, sym='b+', vert=True, whis=1.5,
                 bootstrap=None, usermedians=None, conf_intervals=None,
                 meanline=False, showmeans=False, showcaps=True,
                 showbox=True, showfliers=True, boxprops=None, labels=None,
-                flierprops=None, medianprops=None, meanprops=None):
+                flierprops=None, medianprops=None, meanprops=None,
+                manage_xticks=True):
         """
         Make a box and whisker plot.
 
@@ -3060,14 +3061,15 @@ def boxplot(self, x, notch=False, sym='b+', vert=True, whis=1.5,
                            showcaps=showcaps, showbox=showbox,
                            boxprops=boxprops, flierprops=flierprops,
                            medianprops=medianprops, meanprops=meanprops,
-                           meanline=meanline, showfliers=showfliers)
+                           meanline=meanline, showfliers=showfliers,
+                           manage_xticks=manage_xticks)
         return artists
 
     def bxp(self, bxpstats, positions=None, widths=None, vert=True,
             patch_artist=False, shownotches=False, showmeans=False,
             showcaps=True, showbox=True, showfliers=True,
             boxprops=None, flierprops=None, medianprops=None,
-            meanprops=None, meanline=False):
+            meanprops=None, meanline=False, manage_xticks=True):
         """
         Drawing function for box and whisker plots.
 
@@ -3077,7 +3079,7 @@ def bxp(self, bxpstats, positions=None, widths=None, vert=True,
               patch_artist=False, shownotches=False, showmeans=False,
               showcaps=True, showbox=True, showfliers=True,
               boxprops=None, flierprops=None, medianprops=None,
-              meanprops=None, meanline=False)
+              meanprops=None, meanline=False, manage_xticks=True)
 
         Make a box and whisker plot for each column of *x* or each
         vector in sequence *x*.  The box extends from the lower to
@@ -3156,6 +3158,9 @@ def bxp(self, bxpstats, positions=None, widths=None, vert=True,
             *meanprops*. Not recommended if *shownotches* is also True.
             Otherwise, means will be shown as points.
 
+          manage_xticks : bool, default = True
+            If the function should adjust the xlim and xtick locations.
+
         Returns
         -------
 
@@ -3390,10 +3395,11 @@ def dopatch(xs, ys, **kwargs):
             setlim = self.set_ylim
             setlabels = self.set_yticklabels
 
-        newlimits = min(positions) - 0.5, max(positions) + 0.5
-        setlim(newlimits)
-        setticks(positions)
-        setlabels(datalabels)
+        if manage_xticks:
+            newlimits = min(positions) - 0.5, max(positions) + 0.5
+            setlim(newlimits)
+            setticks(positions)
+            setlabels(datalabels)
 
         # reset hold status
         self.hold(holdStatus)

lib/matplotlib/tests/test_axes.py

@@ -13,7 +13,7 @@
 import matplotlib
 from matplotlib.testing.decorators import image_comparison, cleanup
 import matplotlib.pyplot as plt
-
+from numpy.testing import assert_array_equal
 
 @image_comparison(baseline_images=['formatter_ticker_001',
                                    'formatter_ticker_002',
@@ -1460,6 +1460,20 @@ def test_boxplot_bad_ci_2():
                   conf_intervals=[[1, 2], [1]])
 
 
+@cleanup
+def test_manage_xticks():
+    _, ax = plt.subplots()
+    ax.set_xlim(0, 4)
+    old_xlim = ax.get_xlim()
+    np.random.seed(0)
+    y1 = np.random.normal(10, 3, 20)
+    y2 = np.random.normal(3, 1, 20)
+    ax.boxplot([y1, y2], positions = [1,2],
+               manage_xticks=False)
+    new_xlim = ax.get_xlim()
+    assert_array_equal(old_xlim, new_xlim)
+
+
 @image_comparison(baseline_images=['errorbar_basic', 'errorbar_mixed'])
 def test_errorbar():
     x = np.arange(0.1, 4, 0.5)