On Tue, Oct 1, 2013 at 5:50 AM, Peter Meilstrup <peter.meilst...@gmail.com> wrote: > > On Mon, Sep 30, 2013 at 8:10 AM, Joris Meys <jorism...@gmail.com> wrote: >> >> Regardless of whether "stored as character" is interpreted the R way or the >> ASCII way, the point Joshua makes is rather valid. Mainly because >> read.table has an argument quote with default value \"'. This means that at >> least according to R, everything between either " or ' should be seen as of >> type character and not integer. >> >> The only way these quotes can end up in a .csv file, is when in the >> rendering program (often Excel), these integers are called "character" >> inside the program as well. So they're not treated as integers by the >> person that created the file, so R won't treat them >> as integers either. Note that read.table does read the quoted integers as >> characters, and only afterwards convert those. >> >> So yes, this is an issue with read.table.ffdf more than with R itself. And >> the problem is indeed how integers are treated *the moment they are stored*. >> This refering to the presence/absence of the quote character. > > > This assumes too much about the program that creates the file. > > Quoted numeric values may be necessary in non-American locales which use the > comma as decimal separator. (CSV files written in these locales often use > something other than the comma for the field separator, but this is not > required.) >
Additionally, while CSV is a somewhat nebulous format, most attempts at specifying it are clear that a quoted value, containing no special characters, is to be treated _identically_ to the unquoted version. The reason for the quote is to escape special characters which may be present, not to impart type information. A CSV producing program may simplify the logic of writing a file by always quoting, whether or not the field would contain special characters when rendered. http://www.creativyst.com/Doc/Articles/CSV/CSV01.htm -- "When importing CSV, do not reach down a layer and try to use the quotes to impart type information to fields." Peter ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
