vice.output.show
================

Show a plot of the given quantity referenced by a keyword argument.

**Signature**: x.show(key, xlim = None, ylim = None)

Parameters
----------
x : ``output``
	An instance of this class.
key : ``str`` [case-insensitive]
	The keyword argument. If this is a quantity stored in the history
	attribute, it will be plotted against time by defult. Conversely,
	if it is stored in the mdf attribute, the corresponding stellar
	metallicity distribution function will be plotted.

	Users can also specify an argument of the format "key1-key2"
	where key1 and key2 are elements of the history output. This will
	then plot key1 against key2.
xlim : array-like (contains real numbers) [default : None]
	The x-limits to impose on the shown plot, if any.
ylim : array-like (contains real numbers) [default : None]
	The y-limits to impose on the shown plot, if any.

Raises
------
* KeyError
	-	Key is not found in either history or mdf attributes
* ModuleNotFoundError
	- 	Matplotlib version >= 2.0.x is not found in the user's system.

		.. note:: In python 3.5.x, this will be an ``ImportError``.

Other errors may be raised by matplotlib.pyplot.show.

Notes
-----
This function is **NOT** intended to generate publication quality
plots for users. It is included purely as a convenience function to
allow "quick and dirty" data visualization and inspection of simulation
outputs immediately with only one line of code.

Example Code
------------
>>> import vice
>>> out = vice.output("example")
>>> out.show("dn/d[o/fe]")
>>> out.show("sfr")
>>> out.show("[o/fe]-[fe/h]")