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From Debasish Das <debasish.da...@gmail.com>
Subject Re: LogisticGradient Design
Date Wed, 25 Mar 2015 21:46:50 GMT
Cool...Thanks...It will be great if they move in two code paths just for
the sake of code clean-up

On Wed, Mar 25, 2015 at 2:37 PM, DB Tsai <dbtsai@dbtsai.com> wrote:

> I did the benchmark when I used the if-else statement to switch the
> binary & multinomial logistic loss and gradient, and there is no
> performance hit at all. However, I'm refactoring the LogisticGradient
> code so the addBias and scaling can be done in LogisticGradient
> instead of the input dataset to avoid the second cache. In this case,
> the code will be more complicated, so I will split the code into two
> paths. Will be done in another PR.
>
> Sincerely,
>
> DB Tsai
> -------------------------------------------------------
> Blog: https://www.dbtsai.com
>
>
> On Wed, Mar 25, 2015 at 11:57 AM, Joseph Bradley <joseph@databricks.com>
> wrote:
> > It would be nice to see how big a performance hit we take from combining
> > binary & multiclass logistic loss/gradient.  If it's not a big hit, then
> it
> > might be simpler from an outside API perspective to keep them in 1 class
> > (even if it's more complicated within).
> > Joseph
> >
> > On Wed, Mar 25, 2015 at 8:15 AM, Debasish Das <debasish.das83@gmail.com>
> > wrote:
> >
> >> Hi,
> >>
> >> Right now LogisticGradient implements both binary and multi-class in the
> >> same class using an if-else statement which is a bit convoluted.
> >>
> >> For Generalized matrix factorization, if the data has distinct ratings I
> >> want to use LeastSquareGradient (regression has given best results to
> date)
> >> but if the data has binary labels 0/1 based on domain knowledge
> (implicit
> >> for example, visits no-visits) I want to use a LogisticGradient without
> any
> >> overhead for multi-class if-else...
> >>
> >> I can compare the performance of LeastSquareGradient and multi-class
> >> LogisticGradient on the recommendation metrics but it will be great if
> we
> >> can separate binary and multi-class in Separate
> >> classes....MultiClassLogistic can extend BinaryLogistic but mixing them
> in
> >> the same class is an overhead for users (like me) who wants to use
> >> BinaryLogistic for his application..
> >>
> >> Thanks.
> >> Deb
> >>
>

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