[R] lm question

[Peter Dalgaard BSA]

Bill Simpson <wsi at gcal.ac.uk> writes:

> It seems to me that there is something seriously wrong here since for the
> data I posted (I just re-checked it),
> intercept=-1, slope a=.1, slope b=.2, and slope c = .3
> (These fit the data exactly)
> 
> This leaves aside the comments of Martyn and Brian.

I think you need to be more careful with your signs:


> y[grp=="c"]
[1] -0.19 -0.11 -0.41
>  -1+.3*x[grp=="c"]
[1] -0.19  0.11  0.41


-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._