Hello,
Why does anova.lm sometimes return a p-value and at other times not ? Is it because it recognizes nested models from non-nested ones ?
x<-seq(1,100,1) y<-3*x+rnorm(100) anova(lm(y~x),lm(y~x+I(x^2)),test="F")
Analysis of Variance Table Model 1: y ~ x Model 2: y ~ x + I(x^2) Res.Df RSS Df Sum of Sq F Pr(>F) 1 98 90.449 2 97 90.288 1 0.16117 0.1732 0.6782
anova(lm(y~x),lm(y~I(x^2)+I(x^3)),test="F")
Analysis of Variance Table Model 1: y ~ x Model 2: y ~ I(x^2) + I(x^3) Res.Df RSS Df Sum of Sq F Pr(>F) 1 98 90.4 2 97 7345.7 1 -7255.3 Thanks, Suresh ______________________________________________ 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.
