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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