automatically convert the argument to numpy array if not a dict or a series
removed the test comments, renamed the plot as test, added a test for the data normalization
added the possibility of swapping the axis order and added a visual test for it
added the possibility of swapping the axis order and added a visual test for it
added support for pandas DataFrame and added the corresponding test, corrected a bug for string names in series
added support for pandas DataFrame and added the corresponding test, corrected a bug for string names in series