BUG: Fixes color selection in andrews_curve

doc/source/release.rst

@@ -205,6 +205,8 @@ Improvements to existing features
     wrapper is updated inplace, a copy is still made internally.
     (:issue:`1960`, :issue:`5247`, and related :issue:`2325` [still not
     closed])
+  - Fixed bug in `tools.plotting.andrews_curvres` so that lines are drawn grouped
+    by color as expected.
 
 API Changes
 ~~~~~~~~~~~

pandas/tools/plotting.py

@@ -454,13 +454,14 @@ def f(x):
 
     n = len(data)
     class_col = data[class_column]
+    uniq_class = class_col.drop_duplicates()
     columns = [data[col] for col in data.columns if (col != class_column)]
     x = [-pi + 2.0 * pi * (t / float(samples)) for t in range(samples)]
     used_legends = set([])
 
-    colors = _get_standard_colors(num_colors=n, colormap=colormap,
+    colors = _get_standard_colors(num_colors=len(uniq_class), colormap=colormap,
                                   color_type='random', color=kwds.get('color'))
-
+    col_dict = dict([(klass, col) for klass, col in zip(uniq_class, colors)])
     if ax is None:
         ax = plt.gca(xlim=(-pi, pi))
     for i in range(n):
@@ -471,9 +472,9 @@ def f(x):
         if com.pprint_thing(class_col[i]) not in used_legends:
             label = com.pprint_thing(class_col[i])
             used_legends.add(label)
-            ax.plot(x, y, color=colors[i], label=label, **kwds)
+            ax.plot(x, y, color=col_dict[class_col[i]], label=label, **kwds)
         else:
-            ax.plot(x, y, color=colors[i], **kwds)
+            ax.plot(x, y, color=col_dict[class_col[i]], **kwds)
 
     ax.legend(loc='upper right')
     ax.grid()
@@ -656,10 +657,10 @@ def lag_plot(series, lag=1, ax=None, **kwds):
     ax: Matplotlib axis object
     """
     import matplotlib.pyplot as plt
-    
+
     # workaround because `c='b'` is hardcoded in matplotlibs scatter method
     kwds.setdefault('c', plt.rcParams['patch.facecolor'])
-    
+
     data = series.values
     y1 = data[:-lag]
     y2 = data[lag:]
@@ -1212,20 +1213,20 @@ def __init__(self, data, x, y, **kwargs):
             y = self.data.columns[y]
         self.x = x
         self.y = y
-        
-        
+
+
     def _make_plot(self):
         x, y, data = self.x, self.y, self.data
         ax = self.axes[0]
         ax.scatter(data[x].values, data[y].values, **self.kwds)
-        
+
     def _post_plot_logic(self):
         ax = self.axes[0]
-        x, y = self.x, self.y   
+        x, y = self.x, self.y
         ax.set_ylabel(com.pprint_thing(y))
         ax.set_xlabel(com.pprint_thing(x))
-        
-                
+
+
 class LinePlot(MPLPlot):
 
     def __init__(self, data, **kwargs):
@@ -1658,25 +1659,25 @@ def plot_frame(frame=None, x=None, y=None, subplots=False, sharex=True,
     elif kind == 'kde':
         klass = KdePlot
     elif kind == 'scatter':
-        klass = ScatterPlot 
+        klass = ScatterPlot
     else:
         raise ValueError('Invalid chart type given %s' % kind)
 
     if kind == 'scatter':
-        plot_obj = klass(frame,  x=x, y=y, kind=kind, subplots=subplots, 
-                         rot=rot,legend=legend, ax=ax, style=style, 
+        plot_obj = klass(frame,  x=x, y=y, kind=kind, subplots=subplots,
+                         rot=rot,legend=legend, ax=ax, style=style,
                          fontsize=fontsize, use_index=use_index, sharex=sharex,
-                         sharey=sharey, xticks=xticks, yticks=yticks, 
-                         xlim=xlim, ylim=ylim, title=title, grid=grid, 
-                         figsize=figsize, logx=logx, logy=logy, 
-                         sort_columns=sort_columns, secondary_y=secondary_y, 
+                         sharey=sharey, xticks=xticks, yticks=yticks,
+                         xlim=xlim, ylim=ylim, title=title, grid=grid,
+                         figsize=figsize, logx=logx, logy=logy,
+                         sort_columns=sort_columns, secondary_y=secondary_y,
                          **kwds)
     else:
         if x is not None:
             if com.is_integer(x) and not frame.columns.holds_integer():
                 x = frame.columns[x]
             frame = frame.set_index(x)
-    
+
         if y is not None:
             if com.is_integer(y) and not frame.columns.holds_integer():
                 y = frame.columns[y]
@@ -1691,7 +1692,7 @@ def plot_frame(frame=None, x=None, y=None, subplots=False, sharex=True,
                                grid=grid, logx=logx, logy=logy,
                                secondary_y=secondary_y, title=title,
                                figsize=figsize, fontsize=fontsize, **kwds)
-                                 
+
         else:
             plot_obj = klass(frame, kind=kind, subplots=subplots, rot=rot,
                              legend=legend, ax=ax, style=style, fontsize=fontsize,
@@ -1700,7 +1701,7 @@ def plot_frame(frame=None, x=None, y=None, subplots=False, sharex=True,
                              title=title, grid=grid, figsize=figsize, logx=logx,
                              logy=logy, sort_columns=sort_columns,
                              secondary_y=secondary_y, **kwds)
-                             
+
     plot_obj.generate()
     plot_obj.draw()
     if subplots: