[R] mcmcsamp shortening variable names; how can i turn this feature off?

[Peter Dalgaard]

Andrew Gelman <gelman at stat.columbia.edu> writes:

> I have written a function called mcsamp() that is a wrapper that runs 
> mcmcsamp() and automatically monitors convergence and structures the 
> inferences into vectors and arrays as appropriate.
> 
> But I have run into a very little problem, which is that mcmcsamp() 
> shortens the variable names.  For example:
> 
>  > set.seed (1)
>  > group <- rep (1:5,10)
>  > a <- rnorm (5,-3,3)
>  > y <- rnorm (50, a[group], 2)
>  > fit <- lmer (y ~ 1 + (1 | group))
>  > mcmcsamp(fit)
>      (Intercept) log(sigma^2) log(grop.(In))
> [1,]   -2.771979    0.6909418       1.750876
> attr(,"mcpar")
> [1] 1 1 1
> attr(,"class")
> [1] "mcmc"
> 
> 
> I want "grop" in the above output to be "group", and I want "(In)" to be 
> "(Intercept)".  For my purposes (fitting models in general settings) it 
> is important to have descriptive variable names, and I gain nothing by 
> restricting names to 14 characters.
> 
> Is there a way to turn this feature off?
> Thanks.

Looks like they've been run through abbreviate() (which I thought
would be called abbr(), but apparently not...)

> abbreviate("Peter Dalgaard",5)
Peter Dalgaard
       "PtrDl"

Unfortunately, the 2 parts have been abbreviated separately, so the
long names are lost (in fact never generated). I suppose that it could
be possible to hack Matrix:::abbrvNms so that a long version is
returned in names(colnames(mcmc.out)). You have the sources...

Given how close even atanh(Sbj.(I).Dys) is to filling up the label
field of a Trellis plot, I must say that I think there is a case for
abbreviating. Those names easily get *very* long.


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