Extracting information from ICtab() function of bbmle - r

Question

I'm having some trouble extracting information from the ICtab() function of the bbmle package. Essentially what I'm trying to do is run this function on a series of glm models, then add that output to a master data.frame object. However, while I can extract the $dqAIC and $df parameters from the ICtab() output, I cannot figure out a way to extract the row names themselves (i.e. the names of the models that are being input into ICtab). This is an issue because the ICtab() output is ordered in ascending order of $dqAIC - as such, I cannot pre-label a list or data.frame or matrix with the correct order, as the resulting $dqAIC values are not known ahead of time. To compound the problem, the ICtab() object class does not seem to be able to be coerced into a data.frame or any other object where I might be able to extract row.names() or anything similar.
What I'm looking for is a way to extract all the information from the ICtab() function, as a whole or in 3 pieces (row names, dqAIC values, and df values), and then append it to a master table along with some other information.
Below is a sample of the code I'm trying, along with some test data.
library(bbmle)
library(visreg)
library(splines)
library(foreign)
library(survival)
library(lubridate)
dfun<- function(object) {with(object, sum((weights*residuals^2)[weights>0])/df.residual)}
test.data.1 <- seq(1, 1000, by = 10)
num.days <- seq(1, 100, by = 1)
disp.global <- glm(test.data.1 ~ num.days, family=poisson(link="log"), na.action=na.exclude)
model.1 <- glm(test.data.1 ~ ns(num.days, df = 3), family=poisson(link="log"), na.action=na.exclude)
model.2 <- glm(test.data.1 ~ ns(num.days, df = 6), family=poisson(link="log"), na.action=na.exclude)
testIC <- ICtab(model.1, model.2, dispersion=dfun(disp.global),type="qAIC")
Which gives the result:
> testIC
dqAIC df
model.2 0 7
model.1 5 4
I can pull the dqAIC and df values:
> testIC$dqAIC
[1] 0.000000 5.018875
> testIC$df
[1] 7 4
But I cannot figure out a way to get the "model.2" and "model.1" row names; row.names(testIC) returns nothing, and rownames(testIC) simply returns a NULL:
> row.names(testIC)
> rownames(testIC)
NULL
And as far as I can tell, there is no way to change this output using list(), as.data.frame(), data.frame(), or any other object type to get these row names.
> as.data.frame(testIC)
Error in as.data.frame.default(testIC) :
cannot coerce class ""ICtab"" to a data.frame
As a side note, in the documentation for the bbmle package, there appears to be a function called get.mnames() that should do exactly this - list the model names - however, it does not appear to be included in the bbmle package that is installed (my version matches the version of the documentation, 1.0.18):
> ls("package:bbmle")
[1] "AIC" "AICc" "AICctab" "AICtab" "anova" "BICtab" "call.to.char" "coef" "confint" "deviance"
[11] "formula" "ICtab" "logLik" "mle2" "namedrop" "parnames" "parnames<-" "plot" "predict" "profile"
[21] "qAIC" "qAICc" "relist2" "residuals" "sbeta" "sbetabinom" "sbinom" "simulate" "slice" "slice1D"
[31] "slice2D" "sliceOld" "snbinom" "snorm" "spois" "stdEr" "summary" "update" "vcov"
Any help getting these row names out of the ICtab() result would be greatly appreciated. The above code is simply a sample - what I'm actually doing is running multiple models, with a series of datasets, through the ICtab() function, and I want to put all of that information together in one data.frame object as the result.
Thanks in advance,
Nate

Answer 1

I had the same problem as yours, and I can see that nobody replied to your post.
I am not proud of my solution, it is not very elegant, but it works
class(testIC) <- "data.frame"
rownames(testIC)
I hope it would help someone, someday.

Answer 2

trantsyx' solution actually works fine. It can be combined with the convenient table2office commands from {export} package. Works perfect for me.