BUG: addresses #14855 by fixing color kwarg conflict

DOC: add whats new entry for addressing #14855

TEST: add test for adding color kwarg to scatter_matrix

BUG: add comment that addresses the issue

BUG: set default edgecolor to none and fix facecolor

TST: add facecolor test

BUG: remove new changes and old bug fix

Author: alexandercbooth

doc/source/whatsnew/v0.19.2.txt

@@ -80,3 +80,6 @@ Bug Fixes
 - Explicit check in ``to_stata`` and ``StataWriter`` for out-of-range values when writing doubles (:issue:`14618`)
 - Bug in ``.plot(kind='kde')`` which did not drop missing values to generate the KDE Plot, instead generating an empty plot. (:issue:`14821`)
 - Bug in ``unstack()`` if called with a list of column(s) as an argument, regardless of the dtypes of all columns, they get coerced to ``object`` (:issue:`11847`)
+
+- Bug in ``pd.scatter_matrix()`` could accept either ``color`` or ``c``, but
+  not both (:issue:`14855`)

pandas/tests/plotting/test_misc.py

@@ -76,6 +76,12 @@ def scat(**kwds):
             _check_plot_works(scat, diagonal='hist')
         with tm.assert_produces_warning(UserWarning):
             _check_plot_works(scat, range_padding=.1)
+        with tm.assert_produces_warning(UserWarning):
+            _check_plot_works(scat, color='rgb')
+        with tm.assert_produces_warning(UserWarning):
+            _check_plot_works(scat, c='rgb')
+        with tm.assert_produces_warning(UserWarning):
+            _check_plot_works(scat, facecolor='rgb')
 
         def scat2(x, y, by=None, ax=None, figsize=None):
             return plotting.scatter_plot(df, x, y, by, ax, figsize=None)

pandas/tools/plotting.py

@@ -349,7 +349,6 @@ def scatter_matrix(frame, alpha=0.5, figsize=None, ax=None, grid=False,
     >>> df = DataFrame(np.random.randn(1000, 4), columns=['A','B','C','D'])
     >>> scatter_matrix(df, alpha=0.2)
     """
-    import matplotlib.pyplot as plt
 
     df = frame._get_numeric_data()
     n = df.columns.size
@@ -367,8 +366,8 @@ def scatter_matrix(frame, alpha=0.5, figsize=None, ax=None, grid=False,
     hist_kwds = hist_kwds or {}
     density_kwds = density_kwds or {}
 
-    # workaround because `c='b'` is hardcoded in matplotlibs scatter method
-    kwds.setdefault('c', plt.rcParams['patch.facecolor'])
+    # GH 14855
+    kwds.setdefault('edgecolors', 'none')
 
     boundaries_list = []
     for a in df.columns:
@@ -2864,8 +2863,7 @@ def scatter_plot(data, x, y, by=None, ax=None, figsize=None, grid=False,
     """
     import matplotlib.pyplot as plt
 
-    # workaround because `c='b'` is hardcoded in matplotlibs scatter method
-    kwargs.setdefault('c', plt.rcParams['patch.facecolor'])
+    kwargs.setdefault('edgecolors', 'none')
 
     def plot_group(group, ax):
         xvals = group[x].values