Dear all: I m a newer on R. I have some problem when I use anova function. I use anova function to get Type I SS results, but I also need to get Type III SS results. However, in my code, there is some different between the result of Type I SS and Type III SS. I don’t know why the “seqe” factor disappeared in the result of Type III SS. How can I do?
Here is my example and result. a<-c(1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,14,14) b<-c(1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2) c<-c(2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2) d<-c(2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1) e<-c(1739,1633,1481,1837,1780,2073,1374,1629,1555,1385,1756,1522,1566,1643, 1939,1615,1475,1759,1388,1483,1127,1682,1542,1247,1235,1605,1598,1718 ) KK<-data.frame(subj=as.factor(a), drug=as.factor(b), per=as.factor(c), seqe=as.factor(d), Cmax=e) M<- lm(Cmax ~ seqe+ subj:seqe + per + drug , data=KK) anova(M) drop1(M, test="F") The result of Type I SS: Analysis of Variance Table Response: Cmax Df Sum Sq Mean Sq F value Pr(>F) seqe 1 585 585 0.0160 0.9014 per 1 63175 63175 1.7293 0.2131 drug 1 58149 58149 1.5917 0.2311 seqe:subj 12 634325 52860 1.4469 0.2660 Residuals 12 438395 36533 The result of Type III SS: Single term deletions Model: AUCt ~ seqe + subj:seqe + per + drug Df Sum of Sq RSS AIC F value Pr(F) <none> 63208187 442 per 1 2100484 65308672 441 0.3988 0.5396 drug 1 4714183 67922370 442 0.8950 0.3628 seqe:subj 12 35813062 99021249 430 0.5666 0.8308 Best regards, HY Lee _________________________________________________________________________________________________________ 想知道無聊生活如何大變身嘛? http://tw.promote.mail.yahoo.com/dc/change.html ______________________________________________ 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.