[R] How to get p-values

Peter Dalgaard BSA p.dalgaard at biostat.ku.dk
Mon Aug 5 12:36:14 CEST 2002

Mathias Ditzen <mditzen at zedat.fu-berlin.de> writes:

> Hello all there,
> I want to reimplement (for my personal, still very limited understanding of 
> statistics) the linear regression. Now how do I get the correct values for F 
> and T distributions (something like F.05[1,2], where 1 and 2 are degrees of 
> freedom)? I tried dt and df, but the values I got were not correct. 
> Thank you very much in advance,
> Mathias Ditzen

Functions to give p values all start with p: pf and pt. Be careful to
note that they give the lower tail of the respective distributions. To
get an upper tail, subtract from 1 (or use lower.tail=FALSE). To get
two-tailed tests add both tails together (which is often the same as
multiplying by two).

   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
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