[Rd] Integrating R in OpenOffice

[Duncan Temple Lang]

Hi Harry.

   Thanks for providing the details about the plan.  I'll try to take
a look at some of the Open Office documents in the next week. For the
most part, the inter-system interfaces are the same and only the
mechanics are specific to the host.

  I hope OO doesn't require that we add _all_ S functions to a menu.
If for no other reason, the user will be overwhelmed.  Gnumeric
requires that we register them with the function manager at run-time
which means we can tailor them to the particular session/application.
What one typically wants is a way to tell OO that if it is looking for
a function, ask R does it have that function.  There are a variety of
issues about argument types, etc.  These aside, what we typically want
to have is a that R is embedded in OO and the R-OO bridge provides a
way to marshall a call from OO to R. And we also want a bi-directional
interface so that R can access the OO sheet, etc. from R functions.


  I'll try to briefly address the libR.so issues. 


> Some of the (many) things that I do not have a good grasp on are:
> - which R functions are available to the calling app.  There is a list of 
> functions listed in Chapter 5 of the "Writing R Extensions" doc.
> But there is also a function defined as:
> call_R(char*, long, void**, char**, long*, char**, long, char**);
> which appears to provide access to all R functions.  Is this the case?


- If we have a routine that is responsible for marshalling all calls
from OO to R, we can have it use call_R or alternatively construct and
evaluate an R expression directly in C code. If you look in the
RGnumeric.c file and specifically at the routine
RGnumeric_fixedArgCall(), you'll see an example of the marshalling
routine. This is a more explicit and flexible version of call_R()
and will do error handling correctly!

> 
> - how do R and optional R packages (such as Bioconductor) interact via libR.so?

- If you think of libR.so as simply being a way to embedd R into
another application (just like we can load a library into R), then
that version of R inside a host application runs exactly as it would
as a stand-alone.  One loads any [optional] R package using the
library() function in R and the R engine will take care of all the
details, e.g. loading the .so/.dll for that library, the S code, etc.

The only important thing is that packages in which the C/Fortran code
use routines in R must be installed after R has been built with
libR.so enabled.  This is the default when R is configured with the
--enable-R-shlib option and packages are subsequently installed.  Any
package installed before R was built as a shared library may not work.


> 
> - Do all optional packages have to be defined when building libR.so? (this 
> doesn't sound right)  Or if not, how is libR.so informed that it has to load an 
> additional package?

No. They can be installed whenever needed.

Somebody will have to tell R to load that additional package when it
is needed.  This can be done either in the startup script for R
(i.e. Rprofile) or by the "user" of OO.  Typically, you will add a
function to OO that will load the relevant R packages.  This function
is your OO wrapper to the R functionality.

> 
> - Is this process integral to the runtime so that once Bioconductor or other 
> package is installed via 'R INSTALL ..', libR.so can access them just like R?

Yes. R and libR.so are almost exactly the same. From one point of
view, the difference is how they start - R is a stand alone
application that starts itself; libR.so is started by some other
application.


  This should be very interesting. I'll try to find some time to read
the OO docs and help out.

  D.




Harry Mangalam wrote:
> Hi All,
> 
> A group of about 3-4 of us are looking into the possibility of incorporating R 
> into OpenOffice's (OO) spreadsheet component (sc) .  We wish to use OO's nice 
> ODBC ability to query a postgresql-based gene expression database thus 
> populating an OO sc and then use Bioconductor via R to analyse user-selected 
> parts of this spreadsheet.
> 
> We've looked at and compiled and used RGnumeric (with Duncan's help) to see 
> what's possible under Gnumeric, but AFAIK gnumeric won't have DB connectivity 
> for some time and has neither the finish nor the integration of OO.
> 
> We've reviewed quite a few documents that describe the integration approach and 
> while it seems to be a bit complex (mostly due to UNO - OO's CORBA-like 
> integration strategy), it seems to be quite doable.
> 
> We envision it working ike this:
> 
> - build R as a shared lib - libR.so [trivial - the R team has done this for us]
> 
> - use the UNO framework to direct the writing of an IDL that allows libR.so to 
> be linked into the OO sc runtime [time consuming to digest all the docs and get 
> a feel for how to do this, altho there are some introductory docs at: 
> http://sc.openoffice.org/addin_howto.html
> 
> - write code that will automate the insertion of available R functions into the 
> OO sc menu system. [possibly tricky but mostly tedious..?]
> 
> - write the query interface to the database within OO [pretty easy]
> 
> Some of the (many) things that I do not have a good grasp on are:
> - which R functions are available to the calling app.  There is a list of 
> functions listed in Chapter 5 of the "Writing R Extensions" doc.
> But there is also a function defined as:
> call_R(char*, long, void**, char**, long*, char**, long, char**);
> which appears to provide access to all R functions.  Is this the case?
> 
> - how do R and optional R packages (such as Bioconductor) interact via libR.so?
> 
> - Do all optional packages have to be defined when building libR.so? (this 
> doesn't sound right)  Or if not, how is libR.so informed that it has to load an 
> additional package?
> 
> - Is this process integral to the runtime so that once Bioconductor or other 
> package is installed via 'R INSTALL ..', libR.so can access them just like R?
> 
> 
> 
> -- 
> Cheers, Harry
> Harry J Mangalam - 949 856 2847 (v&f) - hjm at tacgi.com
>              <<plain text preferred>>
> 
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