.. _data:

Data Preparation
****************

You can feed :class:`lvr.Lvr` with:

    1. effects only::

        >>> Lvr([789, 621, 109, 65, 45, 30, 27, 15, 12, 9])

    2. effects with causes::

        >>> Lvr(effects=[789, 621, 109, 65, 45, 30, 27, 15, 12, 9],
        ...         causes=[1, 1, 2, 4, 3, 2, 1 , 4, 2, 1])

    3. with a list_dict::

        >>> Lvr(list_dict=[{'index': 'planet1',
        ...                     'radius': 12, 'mass': 56},
        ...                    {'index': 'planet2',
        ...                     'radius': 20, 'mass': 70}])


Create a list-dict
==================

You may want to turn your dict::

    >>> {'planet1': {'radius': 12, 'mass': 56},
    ...  'planet2': {'radius': 20, 'mass': 70}}

into a list-dict::

    >>> [{'index': 'planet1', 'radius': 12, 'mass': 56},
    ...  {'index': 'planet2', 'radius': 20, 'mass': 70}]


with :func:`~lvr.helpers.list_dict`.

But first, let's consider the surface of each planet as our effect::

    >>> from math import pi
    >>> from lvr.data import exoplanets
    >>> from lvr.helpers import list_dict
    >>> from lvr import Lvr
    >>> eplanets = {planet: dict(surface=4*pi*values['radius']**2,
    ...                          mass=values['mass'])
    ...             for planet, values in exoplanets().items()}

Now we turn our dict into a list-dict::

    >>> prepped = list_dict(eplanets, cause='mass', effect='surface')

which we finally feed :class:`~lvr.Lvr` with::

    >>> eps = Lvr(list_dict=prepped)
    >>> eps
    0.2 => 0.8 [PARETO PRESENT 0.98]