On 8 Feb 2013, at 01:24, "Antonio Silva" <aolinto....@gmail.com> wrote: > # Two-sided p-value should be estimated with > dt(t,summary(fit1)$df[2]) # isn't it?
No, on two counts. > First, dt is the density; you need pt, the cumulative probability, not dt. Second, pt(t, ...) would calculate the one sided lower tail probability. You need twice the upper tail probability for a two-sided p-value. Try 2*pt(t, ..., lower.tail=FALSE) (and if thats wrong by a factor of four i've multiplied instead of dividing ... again ....) S ******************************************************************* This email and any attachments are confidential. Any use...{{dropped:8}} ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.