Presumably from > .Machine$double.eps [1] 2.220446e-16
Whether this means the tail probability is actually that small, or that the routine that computes it can't get any more accuracy than that, you'll have to dig deeper. John .............................................................. John P. Nolan Math/Stat Department 227 Gray Hall, American University 4400 Massachusetts Avenue, NW Washington, DC 20016-8050 jpno...@american.edu voice: 202.885.3140 web: academic2.american.edu/~jpnolan .............................................................. -----r-devel-boun...@r-project.org wrote: ----- To: r-devel <r-devel@r-project.org> From: Michael Friendly Sent by: r-devel-boun...@r-project.org Date: 05/07/2014 10:02AM Subject: [Rd] historical significance of Pr(>Chisq) < 2.2e-16 Where does the value 2.2e-16 come from in p-values for chisq tests such as those reported below? > Anova(cm.mod2) Analysis of Deviance Table (Type II tests) Response: Freq LR Chisq Df Pr(>Chisq) B 11026.2 1 < 2.2e-16 *** W 7037.5 1 < 2.2e-16 *** Age 886.6 8 < 2.2e-16 *** B:W 3025.2 1 < 2.2e-16 *** B:Age 1130.4 8 < 2.2e-16 *** W:Age 332.9 8 < 2.2e-16 *** --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 > -- Michael Friendly Email: friendly AT yorku DOT ca Professor, Psychology Dept. & Chair, Quantitative Methods York University Voice: 416 736-2100 x66249 Fax: 416 736-5814 4700 Keele Street Web: http://www.datavis.ca Toronto, ONT M3J 1P3 CANADA ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
