[R] Strange predicted values ?

[Prof Brian Ripley]

Those are not predicted values, they are fitted values.  Try predicting on 
the same set of variables as you printed.

Please do try to give a small reproducible example so we can see what you 
actually did.

On Thu, 7 Aug 2003, orkun wrote:

> I carried out a logistic regression and found predicted values.
> Then I want to see both predictors (var1,var2..) and predicted values
> in same matrix. In other words, I need to know each combinations
> and predicted values.
> 
> I used:
> cbind(var1,var2,var3,var4,predict(glm.obj,type="resp"))
> 
> I got  a somewhat strange result:
> 
> var1  var2  var3  var4  var5 var6      predicted vals
> ------   -----  ----- -------- -----  -----      -------------------
>   6        6       1      1        1      1            4.24e-07
>   6        6       1      1        1      1            8.37e-11
>   6        6       1      1        1      1            6.8e-07
>    .
>    .
>    .
> 
> I had expected to have a same predicted value for
> same combinations.

Yes, so it's a fair guess that is not what you computed.  But, we can't 
tell what you did do.


-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595