[Rd] write.csv suggestion

Prof Brian Ripley ripley at stats.ox.ac.uk
Thu Jun 30 16:41:08 CEST 2005


I've changed this in R-devel so row.names = FALSE is allowed in 
write.csv[2], but changing col.names, dec, sep and qmethod are not 
allowed.  (col.names is set depending on the setting of row.names.)

So far attempts to change col.names, dec, sep and qmethod are silently 
ignored but I may add some warnings.

On Wed, 29 Jun 2005, McGehee, Robert wrote:

> I didn't want to use a different separator, I wanted to remove
> row.names, as in this example:

OK, but the documentation did explicitly say it was a wrapper for 
row.names = TRUE.

>> data(USArrests)
>> write.csv(USArrests, file = "~/test.csv", row.names = FALSE, col.names
> = TRUE)
> Error in if (col.names) d[[2]] else NULL :
> 	missing value where TRUE/FALSE needed
>
> I only mentioned this suggestion because the above syntax seemed
> reasonable (and self-documenting), but by making the options
> unchangeable, I received an unhelpful error message.
>
> After checking the code, I rewrote the line to this:
>> write.table(USArrests, file = "~/test.csv", sep = ",", row.names =
> FALSE, col.names = TRUE)
>
> This only seemed suboptimal (to me) because one would have to read the
> code to know that the col.names = TRUE option was not being passed along
> to write.table (as I expected).
>
> Best,
> Robert
>
> -----Original Message-----
> From: Prof Brian Ripley [mailto:ripley at stats.ox.ac.uk]
> Sent: Wednesday, June 29, 2005 4:16 PM
> To: McGehee, Robert
> Cc: r-devel at stat.math.ethz.ch
> Subject: Re: [Rd] write.csv suggestion
>
>
> The help page says
>
>      By default there is no column name for a column of row names.  If
>      'col.names = NA' and 'row.names = TRUE' a blank column name is
>      added.  This can be used to write CSV files for input to
>      spreadsheets.  'write.csv' and 'write.csv2' provide convenience
>      wrappers for doing so.
>
> and they are set up to disallow the options they set to be changed.
>
> If you get the option wrong to read a file, you will know soon enough,
> but
> these are to ensure a suitable CSV file gets written (which will not be
> so
> immediately apparent).
>
> Please define `optimal': doing what it was designed for and is
> documented
> to do is according to you not `optimal'.
>
> Why would anyone want to use write.csv to write files with something
> other
> than a comma/semicolon as separator, rather than use write.table?
>
>
> On Wed, 29 Jun 2005, McGehee, Robert wrote:
>
>> Hello all,
>> I had some trouble recently with write.csv because I couldn't change
> one
>> of the default options. A quick view of the code showed that the
>> function was not defined in the most optimal way.
>>
>> Currently,
>> write.csv <- function (..., col.names = NA, sep = ",", qmethod =
>> "double")
>> 	write.table(..., col.names = NA, sep = ",", qmethod = "double")
>>
>> Thus, the options passed along to write.csv are ignored by the
> function
>> (unless in the ...).
>>
>> Perhaps a better way to define the function is as such (similar to
>> read.csv):
>>
>> write.csv <- function (..., col.names = NA, sep = ",", qmethod =
>> "double")
>> 	write.table(..., col.names = col.names, sep = sep, qmethod =
>> qmethod)
>>
>> The same also applies to write.csv2
>>
>> Best,
>> Robert
>>
>>
>>> version
>>         _
>> platform i386-pc-mingw32
>> arch     i386
>> os       mingw32
>> system   i386, mingw32
>> status
>> major    2
>> minor    1.1
>> year     2005
>> month    06
>> day      20
>> language R
>>
>> ______________________________________________
>> R-devel at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>
>>
>
> -- 
> Brian D. Ripley,                  ripley at stats.ox.ac.uk
> Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
> University of Oxford,             Tel:  +44 1865 272861 (self)
> 1 South Parks Road,                     +44 1865 272866 (PA)
> Oxford OX1 3TG, UK                Fax:  +44 1865 272595
>
>

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595



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