R devel - Jan 2007 - Wishlist: Sweave: allow line breaks after forward slashes (PR#9443)

Full_Name: Arne Henningsen
Version: 2.4.0
OS: Linux
Submission from: (NULL) (134.245.140.242)


Sweave does not allow line breaks after forward slashes ("/"). This
might lead
to a long "substring" of a command that cannot be wrapped. Hence,
Sweave either
keeps this long "substring" in the current line and produces a too
long line or
it moves the entire "substring" in the following line and leaves the
current
line rather empty. This problem can be solved if Sweave is allowed to introduce
line breaks after forward slashes. (I guess that this problem can also be solved
if parse() adds a blank after a forward slash.)

Example: 
The following expression cannot be wrapped by Sweave:

mean(myDataframe$myFirstVariable)/mean(myDataframe$mySecondVariable)


Thanks for the great software packages (R, Sweave, ...),
Arne

>>>>> On Thu, 11 Jan 2007 15:07:00 +0100 (CET),
>>>>> ahenningsen  (a) wrote:
  > Full_Name: Arne Henningsen
  > Version: 2.4.0
  > OS: Linux
  > Submission from: (NULL) (134.245.140.242)


  > Sweave does not allow line breaks after forward slashes ("/").
This might lead
  > to a long "substring" of a command that cannot be wrapped.
Hence, Sweave either
  > keeps this long "substring" in the current line and produces a
too long line or
  > it moves the entire "substring" in the following line and
leaves the current
  > line rather empty. This problem can be solved if Sweave is allowed to
introduce
  > line breaks after forward slashes. (I guess that this problem can also be
solved
  > if parse() adds a blank after a forward slash.)

  > Example: 
  > The following expression cannot be wrapped by Sweave:

  > mean(myDataframe$myFirstVariable)/mean(myDataframe$mySecondVariable)


In R 2.5.0 you can use Sweave option keep.source=TRUE to keep the
original formatting of source code, including all indentation and line
breaks -> does this solve your problem?

Best,
Fritz Leisch

On 1/11/2007 9:07 AM, ahenningsen at email.uni-kiel.de
wrote:
> Full_Name: Arne Henningsen
> Version: 2.4.0
> OS: Linux
> Submission from: (NULL) (134.245.140.242)
> 
> 
> Sweave does not allow line breaks after forward slashes ("/").
This might lead
> to a long "substring" of a command that cannot be wrapped. Hence,
Sweave either
> keeps this long "substring" in the current line and produces a
too long line or
> it moves the entire "substring" in the following line and leaves
the current
> line rather empty. This problem can be solved if Sweave is allowed to
introduce
> line breaks after forward slashes. (I guess that this problem can also be
solved
> if parse() adds a blank after a forward slash.)
> 
> Example: 
> The following expression cannot be wrapped by Sweave:
> 
> mean(myDataframe$myFirstVariable)/mean(myDataframe$mySecondVariable)
It's actually deparse() that causes this, but the problem is already 
solved in R-devel (to become R 2.5.0).  If you don't like the formatting 
that deparse() gives to one of your expressions, use the Sweave option
keep.source=TRUE, and your original formatting will be kept for that 
chunk.  Or globally retain your formatting via 
\SweaveOpts{keep.source=TRUE} at the start of your file.

Duncan Murdoch