[Rd] hanging spaces prior to linebreak from cat()

[Simon Urbanek]

On Jul 19, 2011, at 10:44 AM, Tim Triche, Jr. wrote:

> (re-sending after confirming list subscription; apologies if this ends up
> being sent to the list twice)
> 
> Is the expected behavior from cat(), as used below, a hanging space before
> \n at the end of the emitted line?
> 
> firstheader = gsub("\\s+$", "", paste(c("Hybridization REF", s, s),
> collapse = "\t"))
> cat(firstheader, "\n", file = filename)
> 
> When I run the above code, which is followed by appending the contents of a
> data.frame via write.table(), what I get is a file whose first line ends in
> a " \n" (note the space preceding the newline).

Yes, you use the default sep=' ' (space) so, obviously there will be a space before the newline as requested. If you don't want that then you probably want to use sep=''.

Cheers,
Simon


>  I would think that the
> gsub() would have trimmed off this hanging space, but it doesn't.  Is this a
> strange bug or expected behavior?  I have attached the version of cat.R in
> from the SVN checkout I am running as my R build; it doesn't seem awry...
> ?!?
> 
>> sessionInfo()
> R version 2.14.0 Under development (unstable) (2011-04-21 r55577)
> Platform: x86_64-unknown-linux-gnu (64-bit)
> 
> locale:
> [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
> [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
> [5] LC_MONETARY=C              LC_MESSAGES=C
> [7] LC_PAPER=en_US.UTF-8       LC_NAME=C
> [9] LC_ADDRESS=C               LC_TELEPHONE=C
> [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
> 
> attached base packages:
> [1] stats     graphics  grDevices datasets  utils     methods   base
> 
> other attached packages:
> [1] EGC.tools_1.0
> IlluminaHumanMethylation27k.db_1.4.6
> [3] IlluminaHumanMethylation450k.db_1.4.6 org.Hs.eg.db_2.5.0
> [5] RSQLite_0.9-4                         DBI_0.2-5
> [7] AnnotationDbi_1.15.7                  Biobase_2.13.2
> [9] gtools_2.6.2                          reshape_0.8.4
> [11] plyr_1.4
> 
> loaded via a namespace (and not attached):
> [1] annotate_1.31.0   grid_2.14.0       lattice_0.19-17   matrixStats_0.2.2
> [5] methylumi_1.9.5   xtable_1.5-6
> 
> 
> -- 
> If people do not believe that mathematics is simple, it is only because they
> do not realize how complicated life is.
> John von Neumann<http://www-groups.dcs.st-and.ac.uk/~history/Biographies/Von_Neumann.html>
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