[R] bug(?) in str() with strict.width = "cut" when applied to dataframe with numeric component AND factor or character component with longerlevels/strings

[Duncan Murdoch]

On 15/10/2013 7:53 AM, Gerrit Eichner wrote:
> Dear list subscribers,
>
> here is a small artificial example to demonstrate the problem that I
> encountered when looking at the structure of a (larger) data frame that
> comprised (among other components)
>
> a numeric component of elements of the order of > 10000, and
>
> a factor or character component with longer levels/strings:
>
>
> k <- 43      # length of levels or character strings
> n <- 11      # number of rows of data frame
> M <- 10000   # order of magnitude of numerical values
>
> set.seed( 47) # to reproduce the following artificial character string
> longer.char.string <- paste( sample( letters, k, replace = TRUE),
>                                collapse = "")
>
> X <- data.frame( A = 1:n * M,
>                    B = rep( longer.char.string, n))
>
>
> The following call to str() gives apparently a wrong result
>
> str( X, strict.width = "cut")
>
> 'data.frame':   11 obs. of  2 variables:
>    $ A: num  1e+04 2e+04 3e+04 4e+04 5e+04 6e+04 7e+04 8e+04 9e+04 1e+..
>    $ A: num  1e+04 2e+04 3e+04 4e+04 5e+04 6e+04 7e+04 8e+04 9e+04 1e+..
>
>
> whereas the correct result appears for str( X) or if you decrease k to 42
> (isn't that "the answer"? ;-) ) or n to 10 or M to 1000 (or smaller,
> respectively).
>
>
> I tried to dig into the entrails of str.default(), where the cause may
> lie, but got lost pretty soon. So, I am hoping that someone may already
> have a work-around or patch (or dares to dig further)? Thank you for any
> feedback!

I can't reproduce this.  I don't have a 64 bit copy of 3.0.2 handy, but 
I don't see it in 64 bit 3.0.1, or 64 bit 3.0.2-patched, or various 32 
bit versions.

Is it reproducible for you?  It looks to me as though (if it isn't just 
something weird on your system, e.g. an old copy of str() in your 
workspace), it might be a memory protection problem:  something needed 
to be duplicated but wasn't.  But unless I can see it happen, I can't 
start to fix it.

Duncan Murdoch

>
>    Best regards  --  Gerrit
>
> PS:
>
> > sessionInfo()
>
> R version 3.0.2 (2013-09-25)
> Platform: x86_64-w64-mingw32/x64 (64-bit)
>
> locale:
> [1] LC_COLLATE=German_Germany.1252  LC_CTYPE=German_Germany.1252
> [3] LC_MONETARY=German_Germany.1252 LC_NUMERIC=C
> [5] LC_TIME=German_Germany.1252
>
> attached base packages:
> [1] splines   stats     graphics  grDevices utils     datasets
> [7] methods   base
>
> other attached packages:
> [1] nparcomp_2.0     multcomp_1.2-21  mvtnorm_0.9-9996
> [4] car_2.0-19       Hmisc_3.12-2     Formula_1.1-1
> [7] survival_2.37-4  fortunes_1.5-0
>
> loaded via a namespace (and not attached):
> [1] cluster_1.14.4  grid_3.0.2      lattice_0.20-23 MASS_7.3-29
> [5] nnet_7.3-7      rpart_4.1-3     stats4_3.0.2    tools_3.0.2
>
> ---------------------------------------------------------------------
> Dr. Gerrit Eichner                   Mathematical Institute, Room 212
> gerrit.eichner at math.uni-giessen.de   Justus-Liebig-University Giessen
> Tel: +49-(0)641-99-32104          Arndtstr. 2, 35392 Giessen, Germany
> Fax: +49-(0)641-99-32109        http://www.uni-giessen.de/cms/eichner
>
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