Re: [R] Three-dimensional contingency table
Hi, Your example works fine for me. My guess is that you have one of wd, wv, MP, or Count defined as a global variable. This is the main reason the use of attach() is discouraged by many people on this list. The safer thing to do is model1 - glm(Count~MP+wd+wv,poisson. data = frame) -Ista On Sat, Aug 28, 2010 at 10:58 PM, Randklev, Charles charlesrandk...@my.unt.edu wrote: Hi, I am trying to assemble a three-way contingency table examining the presence/absence of mussels, water depth (Depth1 and Depth 2) and water velocity (Flow vs. No Flow). I have written the following code listed below; however, when run the glm I get the following message, Error in model.frame.default(formula = Count ~ MP + wd + wv, drop.unused.levels = TRUE) : variable lengths differ (found for 'MP'). This may be something simple, if so I apologize. Any help would be greatly appreciated. Best, C.R. numbers - c(1134,956,328,529,435,599,27,99) dim(numbers) - c(2,2,2) numbers dimnames(numbers)[[3]] -list(Mussels, No Mussels) dimnames(numbers)[[2]] - list(Flow, No Flow) dimnames(numbers)[[1]] - list(Depth1, Depth2) ftable(numbers) as.data.frame.table(numbers) frame - as.data.frame.table(numbers) names(frame) - c(wd, wv, MP, Count) frame attach(frame) model1 - glm(Count~MP+wd+wv,poisson) __ 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. -- Ista Zahn Graduate student University of Rochester Department of Clinical and Social Psychology http://yourpsyche.org __ 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] Three-dimensional contingency table
I didn't see any error when I ran your code in my computer: numbers - c(1134,956,328,529,435,599,27,99) dim(numbers) - c(2,2,2) numbers , , 1 [,1] [,2] [1,] 1134 328 [2,] 956 529 , , 2 [,1] [,2] [1,] 435 27 [2,] 599 99 dimnames(numbers)[[3]] -list(Mussels, No Mussels) dimnames(numbers)[[2]] - list(Flow, No Flow) dimnames(numbers)[[1]] - list(Depth1, Depth2) ftable(numbers) Mussels No Mussels Depth1 Flow1134435 No Flow 328 27 Depth2 Flow 956599 No Flow 529 99 as.data.frame.table(numbers) Var1Var2 Var3 Freq 1 Depth1FlowMussels 1134 2 Depth2FlowMussels 956 3 Depth1 No FlowMussels 328 4 Depth2 No FlowMussels 529 5 Depth1Flow No Mussels 435 6 Depth2Flow No Mussels 599 7 Depth1 No Flow No Mussels 27 8 Depth2 No Flow No Mussels 99 frame - as.data.frame.table(numbers) names(frame) - c(wd, wv, MP, Count) frame wd wv MP Count 1 Depth1FlowMussels 1134 2 Depth2FlowMussels 956 3 Depth1 No FlowMussels 328 4 Depth2 No FlowMussels 529 5 Depth1Flow No Mussels 435 6 Depth2Flow No Mussels 599 7 Depth1 No Flow No Mussels27 8 Depth2 No Flow No Mussels99 attach(frame) model1 - glm(Count~MP+wd+wv,poisson) summary(model1) Call: glm(formula = Count ~ MP + wd + wv, family = poisson) Deviance Residuals: 1 2 3 4 5 6 7 8 2.5545 -7.0682 -0.13437.48891.05555.7533 -11.0107 -4.2551 Coefficients: Estimate Std. Error z value Pr(|z|) (Intercept) 6.956680.02631 264.414 2e-16 *** MPNo Mussels -0.932370.03466 -26.900 2e-16 *** wdDepth2 0.126290.03127 4.039 5.37e-05 *** wvNo Flow-1.156260.03657 -31.618 2e-16 *** --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 (Dispersion parameter for poisson family taken to be 1) Null deviance: 2279.76 on 7 degrees of freedom Residual deviance: 286.14 on 4 degrees of freedom AIC: 355.18 Number of Fisher Scoring iterations: 4 -- View this message in context: http://r.789695.n4.nabble.com/Three-dimensional-contingency-table-tp2398915p2399062.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] Three-dimensional contingency table
On Aug 28, 2010, at 10:58 PM, Randklev, Charles wrote: Hi, I am trying to assemble a three-way contingency table examining the presence/absence of mussels, water depth (Depth1 and Depth 2) and water velocity (Flow vs. No Flow). I have written the following code listed below; however, when run the glm I get the following message, Error in model.frame.default(formula = Count ~ MP + wd + wv, drop.unused.levels = TRUE) : variable lengths differ (found for 'MP'). This may be something simple, if so I apologize. Any help would be greatly appreciated. Best, C.R. numbers - c(1134,956,328,529,435,599,27,99) dim(numbers) - c(2,2,2) numbers dimnames(numbers)[[3]] -list(Mussels, No Mussels) dimnames(numbers)[[2]] - list(Flow, No Flow) dimnames(numbers)[[1]] - list(Depth1, Depth2) ftable(numbers) as.data.frame.table(numbers) frame - as.data.frame.table(numbers) names(frame) - c(wd, wv, MP, Count) frame attach(frame) model1 - glm(Count~MP+wd+wv,poisson) I don't get that error, so maybe you have more than one MP variable after attaching frame. Have you used ls() recently. If there is an extra MP you should see it there but it shouldn't show up if it is only attached. The attach function is a common cause of perplexing errors. -- David. __ 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.
