Added tests for parallel_plot() use_columns and xticks kwargs

Author: khughitt

pandas/tests/test_graphics.py

@@ -464,6 +464,11 @@ def test_parallel_coordinates(self):
                           colors=('#556270', '#4ECDC4', '#C7F464'))
         _check_plot_works(parallel_coordinates, df, 'Name', 
                           colors=['dodgerblue', 'aquamarine', 'seagreen'])
+        
+        df = read_csv(path, header=None, skiprows=1, names=[1,2,4,8, 'Name'])
+        _check_plot_works(parallel_coordinates, df, 'Name', use_columns=True)
+        _check_plot_works(parallel_coordinates, df, 'Name',
+                          xticks=[1, 5, 25, 125])
 
     @slow
     def test_radviz(self):