Hello,
Just to verify this, we had come across the exact same issue when
converting an XGBoost model to MUltipleAdditiveTrees. This was an issue
specifically with the categorical features that take on integer values. We
ended up subtracting 0.5 from the threshold value on any such split point
on the converted model, so that it would output the same score as the input
model.
On Fri, Jul 16, 2021, 18:19 Roopa Rao <roop...@gmail.com> wrote:
> Okay, thank you for the input
>
> Roopa
>
> On Fri, Jul 16, 2021 at 5:55 AM Alessandro Benedetti <a.benede...@sease.io
> >
> wrote:
>
> > Hi Roopa,
> > I was not able to find why that slack was added.
> > I am not sure why we would like to change the threshold.
> > I would recommend creating a Jira issue and tag at least myself,
> Christine
> > Poerschke and Diego Ceccarelli, so we can discuss and potentially open a
> > pull request.
> >
> > Cheers
> >
> >
> > --------------------------
> > Alessandro Benedetti
> > Apache Lucene/Solr Committer
> > Director, R&D Software Engineer, Search Consultant
> >
> > www.sease.io
> >
> >
> > On Thu, 15 Jul 2021 at 22:24, Roopa Rao <roop...@gmail.com> wrote:
> >
> > > Hi All,
> > >
> > > In LTR for MultipleAdditiveTreeModel what is the purpose of adding
> > > NODE_SPLIT_SLACK
> > > to the threshold?
> > >
> > > Reference: org.apache.solr.ltr.model.MultipleAdditiveTreesModel
> > >
> > > private static final float NODE_SPLIT_SLACK = 1E-6f;
> > >
> > >
> > > public void setThreshold(float threshold) { this.threshold = threshold
> +
> > > NODE_SPLIT_SLACK; }
> > >
> > > We have a feature which can return 0.0 or 1.0
> > >
> > > And model with this tree:
> > >
> > >
> is_xyz_feature,threshold=0.99999994,left=0.0010180053,right=-0.0057609854
> > >
> > > However when Solr actually scores it it is taking it as follows
> > > is_xyz_feature:1.0<= 1.000001, Go Left
> > >
> > > So all the time it goes to left which is incorrect.
> > >
> > > Thanks,
> > > Roopa
> > >
> >
>
