[R] predict() works with the design matrix but throws error with some rows of that matrix

[Damir Cosic]

Right on! I was using the expression for binomial logit. Thank you so much!


On Fri, Nov 20, 2015 at 12:23 PM, peter dalgaard <pdalgd at gmail.com> wrote:

>
> > On 20 Nov 2015, at 17:17 , Damir Cosic <damir.cosic at gmail.com> wrote:
> >
> >
> > To do the same with matrix multiplication, I use the expression
> 1/(1+exp(-xb)):
> >
> > head(1/(1+exp(-(cbind(c(1), mm) %*% coef(m)[2,]))))
> >
> > which should produce the third column above, but it doesn't:
> >
>
> I'm rusty on this, but I suspect that you need
>
> e_i/sum(e_i)
>
> with e_i = exp(x b_i)
>
> (and b_1 == 0 by convention)
>
> -pd
>
> --
> Peter Dalgaard, Professor,
> Center for Statistics, Copenhagen Business School
> Solbjerg Plads 3, 2000 Frederiksberg, Denmark
> Phone: (+45)38153501
> Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com
>
>
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