Tagged Questions

2
votes
0answers
58 views

What tasks should I do when performing a model validation?

I have a mixed model built using Data A below, and now I want to validate the model using Data B. What should I do to actually "validate" the model? ...
1
vote
2answers
177 views

Computing c-index for an external validation of a Cox PH model with R

First off, I'll state that I'm aware many questions get asked about the c-index. I've searched this site and others, and I haven't found an answer for my situation. I can successfully use ...
2
votes
1answer
152 views

Best method to validate a multiply imputed Cox model with R?

This question is with regards to using a test data set to validate an imputed Cox model using R. With a non-imputed data set I would use val.surv() from ...
2
votes
1answer
68 views

Is a different CV arrangement the same as a validation set?

I have a smallish dataset ~ 1500 rows X 500 columns. I've been using a standard 5 fold CV setup where row 1 = CV set1, row2 = CV set2, ... row 6 = CV set1,etc. I'm at the point where I'm trying to ...
4
votes
1answer
859 views

Diagnostic plots for lmer

I am trying to produce a glmm using the lme4 package in R. To validate my model I would like to produce some diagnostic plots ...
2
votes
1answer
311 views

Validation of a linear regression model using R

I have created a multiple linear regression model with R using lm and glm. I am using lm on ...
3
votes
1answer
1k views

Model validation after fitting a negative binomial GLM in R

Ok, I have searched and searched and just have no clue where to start. First, what I would like to do is produce a QQ-plot (or even a readable residual plot) to look at the fit of my model. I guess ...
1
vote
1answer
487 views

How to plot AIC values when using the leaps package?

Does anybody know how to plot all AIC values for different size models, when using the command regsubsets from the package ...
4
votes
2answers
792 views

Variance explained of a mixed effects model in a new data set

I'm using the following function to calculate Edwards R^2 (formula 19 in Edwards et al. 2008) of a mixed effects model (I hope the implementation is correct): ...