on functions can be used with the following losses
<ul class="itemize"><li class="li-itemize">
square loss;
</li><li class="li-itemize">square loss with missing observations;
</li><li class="li-itemize">logistic loss, weighted logistic loss;
</li><li class="li-itemize">multi-class logistic.
</li></ul>
This toolbox can also enforce non-negativity constraints, handle intercepts and
sparse matrices. There are also a few additional undocumented functionalities,
which are available in the source code.
For some c