Mixed linear model with nested and interaction term
The point of the REML method is that there are no sums of squares for the covariance effects.? In fact, there are no sums of squares for any of the effects.? Type III calculates covariance parameters using method of moments, while REML uses restricted maximum likelihood. Steve Denham Senior Director, Bioinformatics Sciences ?MPI Research, Inc.
On Monday, May 7, 2018, 3:41:37 PM EDT, Lin, Heng-An <henganl2 at illinois.edu> wrote:
Hi,? When I using SAS with default REML, it won't display the sum of square.? It only shows covariance parameter estimates for random effect,?for the fixed effect, it still using Type 3.? I am trying using the code below in r to see the difference with smaller and balanced data set?anova(model_MW, ddf="Kenward-Roger")anova(model_MW, type=3)anova(model_MW, type=3, ddf="Kenward-Roger") here is what I got in R?
anova(model_Test, type="3", ddf="Kenward-Roger")Type III Analysis of Variance Table with Kenward-Roger's method? ? ? ? ? ? ? ? ? ?Sum Sq? ?Mean Sq? ?NumDF? ? DenDF? ? F value? ? ?Pr(>F)Treatment? ? 60.219? ? 15.055? ? ?4? ? ? ? ? ? ?4? ? ? ? ? ? 0.8347? ? ?0.5674
and in SAS? (with type3 and KR method)? ? ? ? ? ? ? ? ?df? ? ?Sum Sq? ? ?F value? p-value?Treatment? ?4? ? ?78.9246? ? 0.81? ? ? 0.5801 They seems more similar for F and P value, but the Sum sq still different...not sure why?Sorry for sending repeating email. Thanks for your time again.??: Steve Denham [stevedrd at yahoo.com] ????: 2018?5?7? ?? 06:14 ?: Ben Bolker; Lin, Heng-An ??: r-sig-mixed-models at r-project.org ??: Re: [R-sig-ME] Mixed linear model with nested and interaction term Hi Heng-An, What do you get when you let SAS use the default REML method (i.e. remove the method=type3 statement)?? I suspect that it is much closer to the R results, and would be what most SAS modelers would consider more appropriate for this design. Steve Denham Senior Director, Bioinformatics Sciences ?MPI Research, Inc.
On Friday, May 4, 2018, 4:16:04 PM EDT, Lin, Heng-An <henganl2 at illinois.edu> wrote:
**? Sorry I didn't notice that the format of the previous email was off, so I just send the same email again Here is my SAS syntax and output : proc mixed data=A method=type3; class Location Block Treatment; model Yield= Treatment/ddfm=kr; random Location Location*Treatment Block(Location); run;quit; Source? ? ? ? ? ? ? ? ? ? ? Df? Sum_of_squares? F_value? Treatment? ? ? ? ? ? ? ? 4? ? 46.196951? ? ? ? ? 0.41 Location? ? ? ? ? ? ? ? ? ? 2? ? 4670.0979652? ? 44.74 Location*Treatment? 8? ? 224.44332? ? ? ? ? 1.66 Block (Location)? ? ? ? 9? ? 369.782487? ? ? ? 2.43 Residual? ? ? ? ? ? ? ? ? ? 34? ? 574.051330 And here is R output:
anova(model_MW)
Analysis of Variance Table ? ? ? ? ? ? ? Df? Sum Sq? Mean Sq? F value Treatment 4? 34.847? 8.7118? ? ? 0.5085 I am not sure why the sum of square, and the F- value are different.? Maybe is because I use type III in SAS and in lmer is using REML? I would also like to check the sum of square of other factors as SAS did, is there any way could do this in lmer? I am really new to this, Thanks for your time! Heng-An ________________________________________ ?: R-sig-mixed-models [r-sig-mixed-models-bounces at r-project.org] ?? Lin, Heng-An [henganl2 at illinois.edu] ????: 2018?5?4? ?? 02:36 ?: Ben Bolker ??: r-sig-mixed-models at r-project.org ??: Re: [R-sig-ME] Mixed linear model with nested and interaction term Thanks!! Here is my SAS syntax and output : proc mixed data=A method=type3; class Location Block Treatment; model Yield= Treatment/ddfm=kr; random Location Location*Treatment Block(Location); run;quit; Source DF Sum of Squares Mean Square Error DF F Value Pr > F Treatment 4 46.196951 11.549238 8.0509 0.41 0.7954 Location 2 4670.979652 2335.489826 9.2885 44.74 <.0001 Location*Treatment 8 224.443332 28.055417 34 1.66 0.1442 Block(Location) 9 369.782487 41.086943 34 2.43 0.0295 Residual 34 574.051330 16.883863 . . . And here is R output:
anova(model_MW)
Analysis of Variance Table ? ? ? ? ? ? ? Df? Sum Sq? Mean Sq? F value Treatment 4? 34.847? 8.7118? ? ? 0.5085 I am not sure why the sum of square, and the F- value are different. Maybe is because I use type III in SAS and in lmer is using REML? I would also like to check the sum of square of other factors as SAS did, is there any way could do this in lmer? [[elided Yahoo spam]] Heng-An ________________________________________ ?q: Ben Bolker [bbolker at gmail.com] ?H????: 2018?~5??4?? ?U?? 01:39 ??: Lin, Heng-An ???: r-sig-mixed-models at r-project.org ?D??: Re: [R-sig-ME] Mixed linear model with nested and interaction term This seems like a reasonable model specification. Can you show us the results you're getting from R and SAS, and your SAS syntax (some people here understand that language), so that we can see what looks different? (It would help if you also wrote a few sentences about what you see as the important differences between the results.)
On Fri, May 4, 2018 at 2:30 PM, Lin, Heng-An <henganl2 at illinois.edu> wrote:
Hi all, I am analyzing my data with following model, model1 <- lmer(Yield~Treatment+(1|Location)+(1|Location:Treatment)+(1|Location:Block), data=A) in here, I want to set an random interaction term (Location*treatment) and an random nested term (block nested within location). But I couldn't get similar ANOVA results when I compare the output with SAS porc mixed output. So, I think i might make some mistake in the model in R... Can anyone give me some suggestion? Thanks in advance! Heng-An [[alternative HTML version deleted]]
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