[R] Long command in Sweave

[Gavin Simpson]

On Fri, 2012-04-13 at 17:46 +0800, Wincent wrote: 
> Dear useRs,
> 
> I am writing a vignette for a package, which contains long command like this,
> >reduce(Lipset_cs,"SURVIVAL",c("GNPCAP", "URBANIZA", "LITERACY", "INDLAB", "GOVSTAB"),explain="positive",remainder="exclude",case="CASEID")
> It is longer than the width a page and part of it will become "missing".
> Currently, I have to manually break the command into multiple lines.
> Is there a better way to handle such issue?

Not that I am aware of.

> It seems that others have raised similar question which seems to
> remain unsolved in a satisfactory fashion.
> 
> Thanks for your kind attention in advance.
> 

1) use some spacing and format the code over multiple lines

reduce(Lipset_cs, "SURVIVAL",
       c("GNPCAP", "URBANIZA", "LITERACY", "INDLAB", "GOVSTAB"),
       explain="positive", remainder="exclude", case="CASEID")

Isn't that more readable?! Any good R-aware editor should be able to
handle appropriate formatting of the code. I *never* write long lines in
my editor; I always break the code down to fit roughly into a 72 column
editor window.

2) if you want to force Sweave to respect your new formatting, use
argument `keep.source=TRUE` for the code chunk. Or set it document wide
using \SweaveOpts{option1=value1, option2=value2} etc in the preamble
(where optionX is one of the arguments and valueX what you want to set
that argument too.

Thought IIRC, `keep.source=TRUE` is the default now and as such Sweave
will respect your formatting by default now - before it broke lines
where it could.

In short get out of the habit of writing long lines of R code; you'll be
better in the long run laying your code out logically.

HTH

G

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