Re: [R] Manually calculating values from aov() result

2024-08-07 Thread Rolf Turner
On Wed, 7 Aug 2024 09:58:38 -0400 John Fox wrote: > Dear Brian, > > As Duncan mentioned, the terms type-I, II, and III sums of squares > originated in SAS. ... > The focus, however, shouldn't be on the SSs, or how they're computed, > but on the hypotheses that are tested. The last poin

Re: [R] Manually calculating values from aov() result

2024-08-07 Thread John Fox
Dear Brian, As Duncan mentioned, the terms type-I, II, and III sums of squares originated in SAS. The type-II and III SSs computed by the Anova() function in the car package take a different computational approach than in SAS, but in almost all cases produce the same results. (I slightly regr

Re: [R] Manually calculating values from aov() result

2024-08-07 Thread Ebert,Timothy Aaron
In proc glm, SAS will give both type I and type III sums of squares. You can get type II if you ask. Other procedures in SAS have different output as defaults. Introductory textbooks may only cover type I SS. It is easy to calculate and gets the idea across. In application one of the problems i

Re: [R] Manually calculating values from aov() result

2024-08-07 Thread Duncan Murdoch
Sure, summary(aov(A ~ C, dat)) will give it to you. Duncan Murdoch On 2024-08-07 8:27 a.m., Brian Smith wrote: Hi, Thanks for this information. Is there any way to force R to use Type-1 SS? I think most textbooks use this only. Thanks and regards, On Wed, 7 Aug 2024 at 17:00, Duncan Murdoch

Re: [R] Manually calculating values from aov() result

2024-08-07 Thread Brian Smith
Hi, Thanks for this information. Is there any way to force R to use Type-1 SS? I think most textbooks use this only. Thanks and regards, On Wed, 7 Aug 2024 at 17:00, Duncan Murdoch wrote: > > On 2024-08-07 6:06 a.m., Brian Smith wrote: > > Hi, > > > > I have performed ANOVA as below > > > > dat

Re: [R] Manually calculating values from aov() result

2024-08-07 Thread Duncan Murdoch
On 2024-08-07 6:06 a.m., Brian Smith wrote: Hi, I have performed ANOVA as below dat = data.frame( 'A' = c(-0.3960025, -0.3492880, -1.5893792, -1.4579074, -4.9214873, -0.8575018, -2.5551363, -0.9366557, -1.4307489, -0.3943704), 'B' = c(2,1,2,2,1,2,2,2,2,2), 'C' = c(0,1,1,1,1,1,1,0,1,1)) summary

[R] Manually calculating values from aov() result

2024-08-07 Thread Brian Smith
Hi, I have performed ANOVA as below dat = data.frame( 'A' = c(-0.3960025, -0.3492880, -1.5893792, -1.4579074, -4.9214873, -0.8575018, -2.5551363, -0.9366557, -1.4307489, -0.3943704), 'B' = c(2,1,2,2,1,2,2,2,2,2), 'C' = c(0,1,1,1,1,1,1,0,1,1)) summary(aov(A ~ B * C, dat)) However now I also trie