Loss
----
The loss, or also called "cost", describes the disagreement between the data and the model.
Most commonly, the likelihood (or, to be precise, the *negative log* likelihood)
is used, as the maximum likelihood estimation provides many
beneficial characteristics.
Binned losses require the PDF and data to be binned as well.
Extended losses take the expected count ("yield") of a PDF into account and require the
PDF to be extended in the first place.
.. autosummary::
:toctree: _generated/loss
zfit.loss.UnbinnedNLL
zfit.loss.ExtendedUnbinnedNLL
zfit.loss.BinnedNLL
zfit.loss.ExtendedBinnedNLL
zfit.loss.BinnedChi2
zfit.loss.ExtendedBinnedChi2
zfit.loss.BaseLoss
zfit.loss.SimpleLoss