Finished markevery validator and test cases. Added what's new and example code for markevery

salindersidhu · salindersidhu · commit b73fe0f49943 · 2018-03-07T21:36:26.000-05:00
diff --git a/doc/users/next_whats_new/markevery_prop_cycle.rst b/doc/users/next_whats_new/markevery_prop_cycle.rst
@@ -0,0 +1,7 @@
+Implemented support for axes.prop_cycle property markevery in rcParams
+----------------------------------------------------------------------
+
+The Matplotlib ``rcParams`` settings object now supports configuration
+of the attribute `axes.prop_cycle` with cyclers using the `markevery`
+Line2D object property. An example of this feature is provided at 
+`~matplotlib/examples/lines_bars_and_markers/markevery_prop_cycle.py`
diff --git a/examples/lines_bars_and_markers/markevery_prop_cycle.py b/examples/lines_bars_and_markers/markevery_prop_cycle.py
@@ -0,0 +1,69 @@
+"""
+=================================================================
+Implemented support for prop_cycle property markevery in rcParams
+=================================================================
+
+This example demonstrates a working solution to issue #8576, providing full
+support of the markevery property for axes.prop_cycle assignments through
+rcParams. Makes use of the same list of markevery cases from
+https://matplotlib.org/examples/pylab_examples/markevery_demo.html
+
+Renders a plot with shifted-sine curves along each column with
+a unique markevery value for each sine curve.
+"""
+from __future__ import division
+from cycler import cycler
+import numpy as np
+import matplotlib as mpl
+import matplotlib.pyplot as plt
+import matplotlib.patches as mpatches
+
+# Define a list of markevery cases and color cases to plot
+cases = [None,
+         8,
+         (30, 8),
+         [16, 24, 30],
+         [0, -1],
+         slice(100, 200, 3),
+         0.1,
+         0.3,
+         1.5,
+         (0.0, 0.1),
+         (0.45, 0.1)]
+
+colors = ['#1f77b4',
+          '#ff7f0e',
+          '#2ca02c',
+          '#d62728',
+          '#9467bd',
+          '#8c564b',
+          '#e377c2',
+          '#7f7f7f',
+          '#bcbd22',
+          '#17becf',
+          '#1a55FF']
+
+# Create two different cyclers to use with axes.prop_cycle
+markevery_cycler = cycler(markevery=cases)
+color_cycler = cycler('color', colors)
+
+# Configure rcParams axes.prop_cycle with custom cycler
+custom_cycler = color_cycler + markevery_cycler
+mpl.rcParams['axes.prop_cycle'] = custom_cycler
+
+# Create data points and offsets
+x = np.linspace(0, 2 * np.pi)
+offsets = np.linspace(0, 2 * np.pi, 11, endpoint=False)
+yy = np.transpose([np.sin(x + phi) for phi in offsets])
+
+# Set the plot curve with markers and a title
+fig = plt.figure()
+ax = fig.add_axes([0.1, 0.1, 0.6, 0.75])
+
+for i in range(len(cases)):
+    ax.plot(yy[:, i], marker='o', label=str(cases[i]))
+    ax.legend(bbox_to_anchor=(1.05, 1), loc=2, borderaxespad=0.)
+
+plt.title('Support for axes.prop_cycle cycler with markevery')
+
+plt.show()
diff --git a/lib/matplotlib/rcsetup.py b/lib/matplotlib/rcsetup.py
@@ -541,27 +541,43 @@ def validate_markevery(s):
     Parameters
     ----------
     s : None, int, float, slice, length-2 tuple of ints,
-        length-2 tuple of floats, list
+        length-2 tuple of floats, list of ints
 
     Returns
     -------
     s : None, int, float, slice, length-2 tuple of ints,
-        length-2 tuple of floats, list, ValueError
+        length-2 tuple of floats, list of ints
 
     """
+    # Validate s against type slice
+    if isinstance(s, slice):
+        return s
+    # Validate s against type tuple and list
+    if isinstance(s, Iterable):
+        if isinstance(s, tuple):
+            tupMaxLength = 2
+            tupType = type(s[0])
+            if len(s) != tupMaxLength:
+                raise ValueError("'markevery' tuple must have a length "
+                                 "of %d" % (tupMaxLength))
+            if tupType is int and not all(isinstance(e, int) for e in s):
+                raise ValueError("'markevery' tuple with first element of "
+                                 "type int must have all elements of type "
+                                 "int")
+            if tupType is float and not all(isinstance(e, float) for e in s):
+                raise ValueError("'markevery' tuple with first element of "
+                                 "type float must have all elements of type "
+                                 "float")
+        if isinstance(s, list):
+            if not all(isinstance(e, int) for e in s):
+                raise ValueError("'markevery' list must have all elements "
+                                 "of type int")
+    # Validate s against type float int and None
+    elif not isinstance(s, (float, int)):
+        if s is not None:
+            raise TypeError("'markevery' is of an invalid type")
 
-    if isinstance(s, tuple):
-        # Ensure correct length of 2
-        if len(s) != 2:
-            raise ValueError("'markevery' tuple must be a length of 2")
-        # Ensure that all elements in the tuple are of type int
-        if not all(isinstance(x, int) for x in s):
-            raise ValueError("'markevery' tuple ")
-        # Ensure that all elements in the tuple are of type float
-        elif not all(isinstance(x, float) for x in s):
-            raise ValueError("'markevery' tuple ")
-
-    return s;
+    return s
 
 validate_markeverylist = _listify_validator(validate_markevery)
 
diff --git a/lib/matplotlib/tests/test_rcparams.py b/lib/matplotlib/tests/test_rcparams.py
@@ -329,14 +329,25 @@ def generate_validator_testcases(valid):
                   )
          },
          {'validator': validate_markevery,
-          'success': ((None,None),
-                      (1,1),
-                      (0.1,0.1)
+          'success': ((None, None),
+                      (1, 1),
+                      (0.1, 0.1),
+                      ((1,1), (1,1)),
+                      ((0.1,0.1), (0.1,0.1)),
+                      ([1,2,3], [1,2,3]),
+                      (slice(2), slice(None,2,None)),
+                      (slice(1,2,3), slice(1,2,3))
                       ),
           'fail': (((1,2,3), ValueError),
                    ((0.1,0.2,0.3), ValueError),
+                   ((0.1,2,3), ValueError),
+                   ((1,0.2,0.3), ValueError),
                    ((1,0.1), ValueError),
-                   (('abc'), ValueError)
+                   ((0.1,1), ValueError),
+                   (('abc'), ValueError),
+                   (('a'), ValueError),
+                   ('abc', ValueError),
+                   ('a', ValueError)
                    )
          }
     )
