[R] Strange warning in summary.lm

[ONKELINX, Thierry]

Dear Peter,

Here's an example. Notice the warning in the last two lines of the summary with options(OutDec = ","). It's not present with options(OutDec = ".").

Cheers,

Thierry

> x <- runif(100)
> y <- rnorm(100)
> options(OutDec = ",")
> summary(lm(y~x))

Call:
lm(formula = y ~ x)

Residuals:
      Min        1Q    Median        3Q       Max 
-2,389749 -0,607002  0,006969  0,689535  1,713197 

Coefficients:
            Estimate Std. Error t value Pr(>|t|)
(Intercept)  0,03397    0,17774   0,191    0,849
x           -0,09219    0,29518  -0,312    0,755

Residual standard error: 0,868 on 98 degrees of freedom
Multiple R-Squared: 0.0009943,  Adjusted R-squared: -0.0092 
F-statistic: 0.09754 on 1 and 98 DF,  p-value: 0,7555 

Warning message:
NAs introduced by coercion in: as.double.default(Cf[okP]) 
> options(OutDec = ".")
> summary(lm(y~x))

Call:
lm(formula = y ~ x)

Residuals:
      Min        1Q    Median        3Q       Max 
-2.389749 -0.607002  0.006969  0.689535  1.713197 

Coefficients:
            Estimate Std. Error t value Pr(>|t|)
(Intercept)  0.03397    0.17774   0.191    0.849
x           -0.09219    0.29518  -0.312    0.755

Residual standard error: 0.868 on 98 degrees of freedom
Multiple R-Squared: 0.0009943,  Adjusted R-squared: -0.0092 
F-statistic: 0.09754 on 1 and 98 DF,  p-value: 0.7555 


----------------------------------------------------------------------------
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature and Forest
Cel biometrie, methodologie en kwaliteitszorg / Section biometrics, methodology and quality assurance
Gaverstraat 4
9500 Geraardsbergen
Belgium
tel. + 32 54/436 185
Thierry.Onkelinx op inbo.be
www.inbo.be 

Do not put your faith in what statistics say until you have carefully considered what they do not say.  ~William W. Watt
A statistical analysis, properly conducted, is a delicate dissection of uncertainties, a surgery of suppositions. ~M.J.Moroney

 

> -----Oorspronkelijk bericht-----
> Van: Peter Dalgaard [mailto:P.Dalgaard op biostat.ku.dk] 
> Verzonden: donderdag 19 juli 2007 13:37
> Aan: ONKELINX, Thierry
> CC: Uwe Ligges; r-help op stat.math.ethz.ch
> Onderwerp: Re: [R] Strange warning in summary.lm
> 
> ONKELINX, Thierry wrote:
> > The problem also exists in a clean workspace. But I've found the 
> > troublemaker. I had set options(OutDec = ","). Resetting this to 
> > options(OutDec = ".") solved the problem.
> >
> > Thanks,
> >
> > Thierry
> >   
> Oups. That sounds like there's a bug somewhere. Can you cook 
> up a minimal example which shows the behaviour?
> 
> -- 
>    O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
>   c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
>  (*) \(*) -- University of Copenhagen   Denmark          Ph:  
> (+45) 35327918
> ~~~~~~~~~~ - (p.dalgaard op biostat.ku.dk)                  FAX: 
> (+45) 35327907
> 
> 
>