Deprecated matplotlib.pyplot.hist keyword argument "normed=true" used in pmdarima.arima.ARIMA.plot_diagnostics

[adubpak]

Describe the bug Using the pmdarima.arima.ARIMA.plot_diagnostics always seems to return the following error: "AttributeError: 'Rectangle' object has no property 'normed'"

To Reproduce
Use the plot_diagnostics method

sarima_model = auto_arima(
    train,
    m=13,
    suppress_warnings=True,
    error_action='warn'
)

sarima_model.plot_diagnostics(lags=13)

Versions System: python: 3.8.2 (tags/v3.8.2:7b3ab59, Feb 25 2020, 23:03:10) [MSC v.1916 64 bit (AMD64)] machine: Windows-10-10.0.17763-SP0

Python dependencies: pip: 20.0.2 setuptools: 46.0.0 sklearn: 0.22.2.post1 statsmodels: 0.11.1 numpy: 1.18.1 scipy: 1.4.1 Cython: 0.29.15 pandas: 1.0.1 joblib: 0.14.1 pmdarima: 1.5.3

Expected behavior Return the plot_diagnostics figure (residual, histogram, normal Q-Q and Correlogram)

Actual behavior

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-44-5a958117d242> in <module>
----> 1 sarima_model.plot_diagnostics(lags=13)

c:\users\XXXXXXXX\XXXXXXXX\XXXXXXXX\venv\lib\site-packages\pmdarima\utils\metaestimators.py in <lambda>(*args, **kwargs)
     51 
     52         # lambda, but not partial, allows help() to work with update_wrapper
---> 53         out = (lambda *args, **kwargs: self.fn(obj, *args, **kwargs))
     54         # update the docstring of the returned function
     55         update_wrapper(out, self.fn)

c:\users\XXXXXXXX\XXXXXXXX\XXXXXXXX\venv\lib\site-packages\pmdarima\arima\arima.py in plot_diagnostics(self, variable, lags, fig, figsize)
   1198         # hist needs to use `density` in future when minimum matplotlib has it
   1199         with warnings.catch_warnings(record=True):
-> 1200             ax.hist(resid_nonmissing, normed=True, label='Hist')
   1201 
   1202         kde = gaussian_kde(resid_nonmissing)

c:\users\XXXXXXXX\XXXXXXXX\XXXXXXXX\venv\lib\site-packages\matplotlib\__init__.py in inner(ax, data, *args, **kwargs)
   1541     def inner(ax, *args, data=None, **kwargs):
   1542         if data is None:
-> 1543             return func(ax, *map(sanitize_sequence, args), **kwargs)
   1544 
   1545         bound = new_sig.bind(ax, *args, **kwargs)

c:\users\XXXXXXXX\XXXXXXXX\XXXXXXXX\venv\lib\site-packages\matplotlib\axes\_axes.py in hist(self, x, bins, range, density, weights, cumulative, bottom, histtype, align, orientation, rwidth, log, color, label, stacked, **kwargs)
   6806             if patch:
   6807                 p = patch[0]
-> 6808                 p.update(kwargs)
   6809                 if lbl is not None:
   6810                     p.set_label(lbl)

c:\users\XXXXXXXX\XXXXXXXX\XXXXXXXX\venv\lib\site-packages\matplotlib\artist.py in update(self, props)
   1004 
   1005         with cbook._setattr_cm(self, eventson=False):
-> 1006             ret = [_update_property(self, k, v) for k, v in props.items()]
   1007 
   1008         if len(ret):

c:\users\XXXXXXXX\XXXXXXXX\XXXXXXXX\venv\lib\site-packages\matplotlib\artist.py in <listcomp>(.0)
   1004 
   1005         with cbook._setattr_cm(self, eventson=False):
-> 1006             ret = [_update_property(self, k, v) for k, v in props.items()]
   1007 
   1008         if len(ret):

c:\users\XXXXXXXX\XXXXXXXX\XXXXXXXX\venv\lib\site-packages\matplotlib\artist.py in _update_property(self, k, v)
    999                 func = getattr(self, 'set_' + k, None)
   1000                 if not callable(func):
-> 1001                     raise AttributeError('{!r} object has no property {!r}'
   1002                                          .format(type(self).__name__, k))
   1003                 return func(v)

AttributeError: 'Rectangle' object has no property 'normed'

Additional context The "normed" keyword argument of matplotlib.pyplot.hist is deprecated since version 2.2.0, and has been replaced by the "density" parameter, as can be seen here: https://matplotlib.org/api/_as_gen/matplotlib.pyplot.hist.html#matplotlib.pyplot.hist

It seems to be completely removed from matplotlib version 3.2.0 (released on March 04 2020), but was still present in the documentation of version 3.1.3 (released on February 03 2020).

This argument is used at line 1200 in pmdarima\arima\arima.py Changing the keyword from "normed" to "density" fixes this bug, and the plot_diagnostics method returns the correct figure.

[tgsmith61591]

Thanks for the issue! Would you be willing to submit a PR to fix this?

[adubpak]

Done! Pull request #309 has been created.

[tgsmith61591]

Fixed in #309