# Loss¶

Todo

Fill overview page

 zfit.loss.ExtendedUnbinnedNLL(model, data[, …]) An Unbinned Negative Log Likelihood with an additional poisson term for the zfit.loss.UnbinnedNLL(model, data[, …]) The Unbinned Negative Log Likelihood. zfit.loss.BaseLoss(model, data[, fit_range, …]) A “simultaneous fit” can be performed by giving one or more model, data, fit_range to the loss. zfit.loss.SimpleLoss(func[, deps, …]) Loss from a (function returning a) Tensor. EXPERIMENTAL! Enable a loss penalty if the loss is NaN, which can push back the minimizer.