Questions tagged [car]

CAR refers to the Conditional Auto-regressive models, which is used in spatial statistics.

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28 views

Out-of-sample prediction in conditional autoregressive models

I am interested in fitting a conditional autoregressive model to a dataset where observations are grouped by regions, then performing cross-validation by holding out all observations from a single ...
3
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1answer
61 views

why does ignoring spatial autocorrelation lead to spurious significance

In spatial statistics one often hears the statements like the following: unaccounted for spatial autocorrelation may lead to spurious significance / understimated uncertainty / too narrow ...
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653 views

Understanding the Anova (car package) output in r

I am running a two-way anova test using Anova from car package. My data looks like this: ...
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66 views

Strength Parameter in ICAR Spatial Model

As I understand it, the parameter $\alpha \in [0, 1]$ that controls strength of spatial association in a CAR model gets set to 1 in an Intrinsic CAR model. Does this mean that an ICAR model cannot/...
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1answer
479 views

Difference between residual plots in plot(gam.object) and crplots(model)?

Both plot(gam.object)(regardless of whether in mgcv or gam) and ...
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2answers
361 views

Probing effects in a multivariate multiple regression

I'm trying to run a multivariate multiple regression in R, i.e. including multiple predictors and multiple outcome variables in the same linear regression model. Does anybody know how to pull out the ...
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1answer
642 views

Presenting results from tree classification methods

I am writing my thesis about binge drinking at my universitity. I have done a survey and collected 957 instances with 29 variables that could be interesting. I also got a binary value for binge ...
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118 views

whether the car::Anova function can be used for GLMM

Now, I am running a generalized linear mixed model using lme4 package. I have three category factors (factor 1 has three levels, factor 2 has two levels, factor 3 has five levels). And I want to ...
2
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0answers
320 views

Implementing a hierarchical bayesian model with latent independent and dependent variables for spatial analysis (in stan)

I am moderately familiar with frequentist hierarchical modeling, structural equation modeling, and hierarchical structural equation modeling. I am also moderately familiar with bayesian graphical ...
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235 views

leverage.plot() R - CAR package

I'm trying to complete a homework regarding added-variables and leverage plots using the CAR package. In the documentation of the ...
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1k views

Will Tukey multiple comparison be the same for different types of Sum Of Squares of ANOVA for an unbalanced design

I am working on Two-Way ANOVA for an unbalanced design. Will Tukey multiple comparison be the same for different types (I, II & III) of Sum Of Squares of ANOVA for an unbalanced design. I am ...
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361 views

Model checking for Spatial CAR (Conditional Autoregressive) model

We assume our data follow the model: $$ Y = X\beta +\varepsilon $$ In spatial CAR (SAR) model, we assume that the errors $\varepsilon$ are correlated in a spatial setting. Let's say that we model ...
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558 views

Different p-values between Wald Z and Wald Chisquare

I have used lme4 for mixed effects models of reaction times and accuracy rates. I could not use lmerTest because the type of model I was using are not yet implemented there (problem with predictors ...