Re: [R] MANOVA and Extra Sums-of-Squares Tests
Hi John, Thanks again. That looks like an easy and convenient approach. Regards, Chris -- View this message in context: http://r.789695.n4.nabble.com/MANOVA-and-Extra-Sums-of-Squares-Tests-tp4470077p4472265.html Sent from the R help mailing list archive at Nabble.com. __ 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.
[R] MANOVA and Extra Sums-of-Squares Tests
I would like to conduct an extra sum-of -squares test that compares a full MANOVA model (with all 1st order interactions) to a reduced model (no interactions) to determine if I can drop all interactions at the same time. This is analagous to an extra sum-of-squares F-test in ANOVA, but instead using MANOVA. Is there a command in R that does this? If not, is there a command that calculates residual sum-of-squares and cross-product matrices? Thanks. -- View this message in context: http://r.789695.n4.nabble.com/MANOVA-and-Extra-Sums-of-Squares-Tests-tp4470077p4470077.html Sent from the R help mailing list archive at Nabble.com. __ 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.
Re: [R] MANOVA and Extra Sums-of-Squares Tests
Dear chris33, You can use the anova() function to compare the two multivariate linear models. Alternatively, the Anova() function in the car package will compute type II or type III MANOVA tests, which aren't quite what you're asking about. I hope this helps, John John Fox Sen. William McMaster Prof. of Social Statistics Department of Sociology McMaster University Hamilton, Ontario, Canada http://socserv.mcmaster.ca/jfox/ On Tue, 13 Mar 2012 12:31:25 -0700 (PDT) chris33 malachow...@gmail.com wrote: I would like to conduct an extra sum-of -squares test that compares a full MANOVA model (with all 1st order interactions) to a reduced model (no interactions) to determine if I can drop all interactions at the same time. This is analagous to an extra sum-of-squares F-test in ANOVA, but instead using MANOVA. Is there a command in R that does this? If not, is there a command that calculates residual sum-of-squares and cross-product matrices? Thanks. -- View this message in context: http://r.789695.n4.nabble.com/MANOVA-and-Extra-Sums-of-Squares-Tests-tp4470077p4470077.html Sent from the R help mailing list archive at Nabble.com. __ 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. __ 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.
Re: [R] MANOVA and Extra Sums-of-Squares Tests
Hi John, Thanks for your response. The anova funtion will not work in my case, because I have multiple response variables. In other words, I would like to conduct an extra sums-of-squares and cross-products test between the following models: FULL.MODEL: (Y1, Y2, Y3, Y4, Y5) as a function of X1 + X2 + X3 + X4 + X1*X2 +X1*X3 + X1*X4 REDUCED.MODEL: (Y1, Y2, Y3, Y4, Y5) as a function of X1 + X2 + X3 + X4 So, I suppose that I would need to calculate the residual sum-of-squares and cross-product matrices for each of these models as a start. Any ideas how I would go about this in R? Thanks again, Chris -- View this message in context: http://r.789695.n4.nabble.com/MANOVA-and-Extra-Sums-of-Squares-Tests-tp4470077p4470459.html Sent from the R help mailing list archive at Nabble.com. __ 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.
Re: [R] MANOVA and Extra Sums-of-Squares Tests
Dear chris33, Well, actually as I said, the anova() function *will* do what you want. You can fit multivariate linear models with lm(), mod.1 - lm(cbind(Y1, Y2, Y3, Y4, Y5) ~ X1*X2 +X1*X3 + X1*X4) mod.2 - lm(cbind(Y1, Y2, Y3, Y4, Y5) ~ X1 + X2 + X3 + X4) and then use anova() to get multivariate tests, anova(mod.1, mod.2) See ?anova.mlm for more information. Best, John On Tue, 13 Mar 2012 14:49:01 -0700 (PDT) chris33 malachow...@gmail.com wrote: Hi John, Thanks for your response. The anova funtion will not work in my case, because I have multiple response variables. In other words, I would like to conduct an extra sums-of-squares and cross-products test between the following models: FULL.MODEL: (Y1, Y2, Y3, Y4, Y5) as a function of X1 + X2 + X3 + X4 + X1*X2 +X1*X3 + X1*X4 REDUCED.MODEL: (Y1, Y2, Y3, Y4, Y5) as a function of X1 + X2 + X3 + X4 So, I suppose that I would need to calculate the residual sum-of-squares and cross-product matrices for each of these models as a start. Any ideas how I would go about this in R? Thanks again, Chris -- View this message in context: http://r.789695.n4.nabble.com/MANOVA-and-Extra-Sums-of-Squares-Tests-tp4470077p4470459.html Sent from the R help mailing list archive at Nabble.com. __ 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. __ 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.
