Re: [R] Type II and III sums of squares with Error in AOV
A multistratum aov() fit is just a list of aov() fits, so you can apply functions such as Anova to the individual strata. However, why do you want types II and III sums of squares? It is usual to do this type of analysis only with balanced designs. In the cases I can envisage that these make any sense, they are the same as type I (and in cases with only one treatment effect, they always are). On Tue, 8 Nov 2005, Jarrett Byrnes wrote: I've recently run into the problem of using aov with nested factors, and wanting to get the type II and III sums of squares. Normally Anova from the car package would do fine, but it doesn't like having an Error included, so my.aov -aov(Response ~ Treatment + Error(Treatment:Replicate)) Anova(my.aov, type=II) yields Error in Anova(nested.anova) : no applicable method for Anova And lm does not take Error as an argument. Nor does log()! Is that relevant? Error in eval(expr, envir, enclos) : couldn't find function Error Is there a way to get these additional types of sums of squares when Error is included in an aov model? Have you read the reference on the aov help page? That might be a good step to deepening your understanding of what Error() does. -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UKFax: +44 1865 272595 __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] Type II and III sums of squares with Error in AOV
Prof Brian Ripley [EMAIL PROTECTED] writes: A multistratum aov() fit is just a list of aov() fits, so you can apply functions such as Anova to the individual strata. However, why do you want types II and III sums of squares? It is usual to do this type of analysis only with balanced designs. In the cases I can envisage that these make any sense, they are the same as type I (and in cases with only one treatment effect, they always are). I was about to make a similar comment. A possible exception is ANCOVA where you likely want to test both the within-stratum effect of a covariate and the effect of design factors adjusted for the covariate. On Tue, 8 Nov 2005, Jarrett Byrnes wrote: I've recently run into the problem of using aov with nested factors, and wanting to get the type II and III sums of squares. Normally Anova from the car package would do fine, but it doesn't like having an Error included, so my.aov -aov(Response ~ Treatment + Error(Treatment:Replicate)) Anova(my.aov, type=II) yields Error in Anova(nested.anova) : no applicable method for Anova And lm does not take Error as an argument. Nor does log()! Is that relevant? Error in eval(expr, envir, enclos) : couldn't find function Error Is there a way to get these additional types of sums of squares when Error is included in an aov model? Have you read the reference on the aov help page? That might be a good step to deepening your understanding of what Error() does. -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UKFax: +44 1865 272595 __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html -- O__ Peter Dalgaard Øster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] Type II and III sums of squares with Error in AOV
While my original design was balanced, I lost several replicates due to a storm, making the whole thing unbalanced. Ah, the realities of ecology. So, how does one look at individual strata, and then how would one report an aggregate test of the effect in general? On Nov 9, 2005, at 4:38 AM, Peter Dalgaard wrote: Prof Brian Ripley [EMAIL PROTECTED] writes: A multistratum aov() fit is just a list of aov() fits, so you can apply functions such as Anova to the individual strata. However, why do you want types II and III sums of squares? It is usual to do this type of analysis only with balanced designs. In the cases I can envisage that these make any sense, they are the same as type I (and in cases with only one treatment effect, they always are). I was about to make a similar comment. A possible exception is ANCOVA where you likely want to test both the within-stratum effect of a covariate and the effect of design factors adjusted for the covariate. On Tue, 8 Nov 2005, Jarrett Byrnes wrote: I've recently run into the problem of using aov with nested factors, and wanting to get the type II and III sums of squares. Normally Anova from the car package would do fine, but it doesn't like having an Error included, so my.aov -aov(Response ~ Treatment + Error(Treatment:Replicate)) Anova(my.aov, type=II) yields Error in Anova(nested.anova) : no applicable method for Anova And lm does not take Error as an argument. Nor does log()! Is that relevant? Error in eval(expr, envir, enclos) : couldn't find function Error Is there a way to get these additional types of sums of squares when Error is included in an aov model? Have you read the reference on the aov help page? That might be a good step to deepening your understanding of what Error() does. -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UKFax: +44 1865 272595 __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html -- O__ Peter Dalgaard Øster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] Type II and III sums of squares with Error in AOV
On Wed, November 9, 2005 14:38, Peter Dalgaard wrote: Prof Brian Ripley [EMAIL PROTECTED] writes: A multistratum aov() fit is just a list of aov() fits, so you can apply functions such as Anova to the individual strata. However, why do you want types II and III sums of squares? It is usual to do this type of analysis only with balanced designs. In the cases I can envisage that these make any sense, they are the same as type I (and in cases with only one treatment effect, they always are). I was about to make a similar comment. A possible exception is ANCOVA where you likely want to test both the within-stratum effect of a covariate and the effect of design factors adjusted for the covariate. May I offer a more mundane reason for asking for Type II and PRIMARILY Type III SS? The editor of that particular journal who is hooked on a specific type of software and knows only about what he/she gets from the software? Sincerely, Ioannis -- Ioannis C. Dimakos University of Patras Department of Elementary Education Patras, GR-26500 GREECE http://www.elemedu.upatras.gr/dimakos/ http://yannishome.port5.com/ __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
[R] Type II and III sums of squares with Error in AOV
I've recently run into the problem of using aov with nested factors, and wanting to get the type II and III sums of squares. Normally Anova from the car package would do fine, but it doesn't like having an Error included, so my.aov -aov(Response ~ Treatment + Error(Treatment:Replicate)) Anova(my.aov, type=II) yields Error in Anova(nested.anova) : no applicable method for Anova And lm does not take Error as an argument. Error in eval(expr, envir, enclos) : couldn't find function Error Is there a way to get these additional types of sums of squares when Error is included in an aov model? __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
