[R] still problems with predict!

[Anne]

Hi all,

I still have problems with the predict function by setting up the values on
which I want to predict

ie:
original df: p1 (193 obs) variates y x1 x2

rm(list=ls())
x1<-rnorm(193)
x2<-runif(193,-5,5)
y<-rnorm(193)+x1+x2
p1<-as.data.frame(cbind(y,x1,x2))
p1
             y         x1         x2
1   -0.6056448 -0.1113607 -0.5859728
2   -4.2841793 -1.0432688 -3.3116807
......
192 -1.3228239  1.0263013 -2.7801324
193  1.8736683  1.0480632  0.4746959

newdf<-data.frame(x1= seq(min( p1$x1),max( p1$x1),length=10),
                              x2=rep(median( p1$x2),10) )
pr<-predict(g<-lm(p1$y~p1$x1+p1$x2) ,newdf, se.fit = TRUE)

newdf
           x1         x2
1  -2.3844149 -0.2594991
2  -1.8388635 -0.2594991
...
9   1.9799963 -0.2594991
10  2.5255477 -0.2594991

pr$fit
1   -0.6766906
2   -4.4198864
.....
192 -1.6531906
193  1.6395442

so apparently the predict() function did not take up the new data.frame


I looked up with conflicts() to see if I had masked objects in the search
path potentially causing this problem
but found none



Thanks and a good week end! (I for one need it)
Anne
----------------------------------------------------
Anne Piotet
Tel: +41 79 359 83 32 (mobile)
Email: anne.piotet at m-td.com
---------------------------------------------------
M-TD Modelling and Technology Development
PSE-C
CH-1015 Lausanne
Switzerland
Tel: +41 21 693 83 98
Fax: +41 21 646 41 33