[R] excel files and R

[Duncan Murdoch]

On Wed, 25 Jun 2003 11:51:44 +0100 (BST), you wrote in message
<Pine.LNX.4.44.0306251149030.2122-100000 at gannet.stats>:

>
>The Excel .xls format is poorly documented, probably deliberately
>obfuscated.  A direct interface is on the TODO list: it should be quite
>easy in Windows and possible in other OSes (there is code in Gnumeric, for
>example).  In any case, this is a lot harder than the interfaces currently 
>in foreign.

The OpenOffice web site has reasonably complete documentation on this
web page:  <http://sc.openoffice.org>.  It skips some of the more
obscure features, but those probably wouldn't be of interest to R
either.

It looks to me as though it would be relatively easy to write (in R,
using the streams code) a reader that could read strings and numbers.
Interpreting formulas would be a lot harder.  (It's possible the last
value of a formula is stored in the .xls file, in which case it would
be easily read too.)

One thing I'm not sure about:  recent .xls versions store strings in
Unicode.  Does R have cross-platform Unicode support?

Duncan