Bug? (PR#1710)

[Lauri.Mehtatalo@metla.fi]

Hi,

I tried to do a multiple linear model from the example 
dataset Formaldehyde. However, the function lm() did not 
estimate the coefficient of the term carb^2. The same 
problem occurred with the (nlme)dataset Pixel with both 
function lme() and lm(). I am using the windows version of 
R 1.5.1

Lauri Mehtatalo

The Formaldehyde example:
> data(Formaldehyde)
> lm(optden~carb+carb^2,data=Formaldehyde)

Call:
lm(formula = optden ~ carb + carb^2, data = 
Formaldehyde)

Coefficients:
(Intercept)         carb  
   0.005086     0.876286  

The Pixel example:

> {pkg <- select.list(sort(.packages(all.available = TRUE)))
+ if(nchar(pkg)) library(pkg, character.only=TRUE)}
Loading required package: nls 
Loading required package: lattice 
> data(Pixel)
>coef(lme(pixel~day+day^2,data=Pixel,random=list(Dog=
~day,Side=~1)))
     (Intercept)         day
1/L     1048.995  0.32564928
1/R     1043.659  0.32564928
10/L    1144.898 -0.63867455
10/R    1099.883 -0.63867455
2/L     1054.011  0.65786288
2/R     1048.726  0.65786288
3/L     1065.000  0.45552014
3/R     1075.759  0.45552014
4/L     1088.173  0.93300591
4/R     1088.854  0.93300591
5/L     1125.918 -0.91429707
5/R     1129.309 -0.91429707
6/L     1112.721 -0.72735611
6/R     1094.164 -0.72735611
7/L     1133.443 -1.69593549
7/R     1156.943 -1.69593549
8/L     1101.205  0.05435070
8/R     1087.689  0.05435070
9/L     1093.513  0.05987474
9/R     1071.482  0.05987474
> coef(lm(pixel~day+day^2,data=Pixel))
(Intercept)         day 
1076.820678    1.341873  
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Lauri Mehtätalo
Metsäntutkimuslaitos
Joensuun tutkimuskeskus
PL 68 (Yliopistokatu 7)
80101 JOENSUU
lauri.mehtatalo@metla.fi
p. 013-251 4110
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