Fix rc grid parameter inconsistency

lib/matplotlib/axes/_base.py

@@ -890,7 +890,7 @@ def cla(self):
         self.collections = []  # collection.Collection instances
         self.containers = []
 
-        self.grid(self._gridOn)
+        self.grid(self._gridOn, which=rcParams['axes.grid.which'])
         props = font_manager.FontProperties(size=rcParams['axes.titlesize'])
 
         self.titleOffsetTrans = mtransforms.ScaledTranslation(

lib/matplotlib/axis.py

@@ -70,7 +70,7 @@ def __init__(self, axes, loc, label,
                  labelsize=None,
                  labelcolor=None,
                  zorder=None,
-                 gridOn=None,  # defaults to axes.grid
+                 gridOn=None,  # defaults to axes.grid depending on axes.grid.which
                  tick1On=True,
                  tick2On=True,
                  label1On=True,
@@ -85,7 +85,12 @@ def __init__(self, axes, loc, label,
         artist.Artist.__init__(self)
 
         if gridOn is None:
-            gridOn = rcParams['axes.grid']
+            if major and (rcParams['axes.grid.which'] in ('both','major')):
+                gridOn = rcParams['axes.grid']
+            elif (not major) and (rcParams['axes.grid.which'] in ('both','minor')):
+                gridOn = rcParams['axes.grid']
+            else :
+                gridOn = False
 
         self.set_figure(axes.figure)
         self.axes = axes
@@ -733,8 +738,8 @@ def cla(self):
         self.callbacks = cbook.CallbackRegistry()
 
         # whether the grids are on
-        self._gridOnMajor = rcParams['axes.grid']
-        self._gridOnMinor = False
+        self._gridOnMajor = rcParams['axes.grid'] and (rcParams['axes.grid.which'] in ('both','major'))
+        self._gridOnMinor = rcParams['axes.grid'] and (rcParams['axes.grid.which'] in ('both','minor'))
 
         self.label.set_text('')
         self._set_artist_props(self.label)

lib/matplotlib/rcsetup.py

@@ -419,6 +419,7 @@ def validate_hinting(s):
 validate_movie_frame_fmt = ValidateInStrings('animation.frame_format',
     ['png', 'jpeg', 'tiff', 'raw', 'rgba'])
 
+validate_axis_locator = ValidateInStrings('major', ['minor','both','major'])
 
 def validate_bbox(s):
     if type(s) is str:
@@ -577,6 +578,10 @@ def __call__(self, s):
     'axes.titlesize':        ['large', validate_fontsize],  # fontsize of the
                                                             # axes title
     'axes.grid':             [False, validate_bool],   # display grid or not
+    'axes.grid.which':       ['major', validate_axis_locator],  # set wether the gid are by
+                                                                # default draw on 'major'
+                                                                # 'minor' or 'both' kind of
+                                                                # axis locator
     'axes.labelsize':        ['medium', validate_fontsize],  # fontsize of the
                                                              # x any y labels
     'axes.labelweight':      ['normal', str],  # fontsize of the x any y labels

lib/matplotlib/tests/test_axes.py

@@ -1664,6 +1664,29 @@ def make_patch_spines_invisible(ax):
     host.tick_params(axis='x', **tkw)
 
 
+@cleanup
+def test_rcparam_grid_minor():
+    orig_grid = matplotlib.rcParams['axes.grid']
+    orig_locator = matplotlib.rcParams['axes.grid.which']
+
+    matplotlib.rcParams['axes.grid'] = True
+
+    values = (
+        (('both'), (True, True)),
+        (('major'), (True, False)),
+        (('minor'), (False, True))
+        )
+
+    for locator, result in values:
+        matplotlib.rcParams['axes.grid.which'] = locator
+        fig = plt.figure()
+        ax = fig.add_subplot(1, 1, 1)
+        assert((ax.xaxis._gridOnMajor, ax.xaxis._gridOnMinor) == result)
+
+    matplotlib.rcParams['axes.grid'] = orig_grid
+    matplotlib.rcParams['axes.grid.which'] = orig_locator
+
+
 @cleanup
 def test_vline_limit():
     fig = plt.figure()