Suggestion for interface change

[fangohr]

Pandas allows to give an axis handle to matplotlib axis objects to the plotting method. Like this:

%matplotlib inline

import matplotlib.pyplot as plt

import pandas as pd
import numpy as np

fig, ax = plt.subplots(1, 1)
df = pd.DataFrame(np.random.rand(5, 3), columns=['a', 'b', 'c'])
ax.get_xaxis().set_visible(False)   # Hide Ticks
df.plot(ax=ax)

I suggest to use the same method and the same name (ax) in this tool to allow the user to fine tune the plot, and put the plot into an existing axis object.

It looks like this is 'just' a matter of renaming predefined_axis to ax?