.. _output-page:

Output
======

The output of a truth discovery algorithm in this library is a :any:`Result`
object. The most important attributes of :any:`Result` objects are ``trust``
and ``belief``, which are dictionaries containing the trust and belief scores
for each source and claim. See the example below for their format.

An important method is :any:`get_most_believed_values`, which returns (a
generator of) the values with highest belief score for a given variable.

See the :any:`Result` class for full documentation on the available attributes
and methods. The example below shows the format of the trust and belief
dictionaries, after running an algorithm on the first example dataset from
:ref:`input-page`.

    >>> results = AverageLog().run(mydata)
    >>> results.trust
    {'source 1': 0.2637321368777009, 'source 2': 0.52146101879096, 'source 3':
    0.7681758936725634, 'source 4': 1.0}
    >>> results.belief["x"]
    {4: 0.14915492164635274, 3: 1.0}
    >>> results.belief["y"]
    {7: 0.4440695965138328, 6: 0.5655545941885707}
    >>> results.belief["z"]
    {5: 0.7293600806789093, 8: 0.5655545941885707}
    >>> results.time_taken
    0.006222724914550781
    >>> results.iterations
    20
    >>> list(results.get_most_believed_values("x"))
    [3]
    >>> list(results.get_most_believed_values("y"))
    [6]
    >>> list(results.get_most_believed_values("z"))
    [5]
    >>> results.filter(sources=["source 1", "source 3"]).trust
    {'source 1': 0.2637321368777009, 'source 3': 0.7681758936725634}
    >>> results.filter(variables=["x"]).belief
    {'x': {4: 0.14915492164635274, 3: 1.0}}
    >>> results.get_trust_stats()
    (0.6383422623353061, 0.2746120273343826)

Difference between two set of results
-------------------------------------

It is possible to compare two sets of results using the :any:`ResultDiff`
class.

    >>> from truthdiscovery import ResultDiff
    >>> diff = ResultDiff(res1, res2)

A :any:`ResultDiff` object has attributes ``trust``, ``belief``, ``time_taken``
and ``iterations``, as the :any:`Result` objects do. The format of each
attribute is the same as in :any:`Result`, but gives the increase in
trust/belief/time taken/number of iterations between the first and second set
of results (the numbers are negative in the case of a decrease).

This is useful for comparing results after making a small change to the input
dataset: for example to study the effects on trust scores of a source making an
additional claim, or the effects on belief when adding a new variable.