[Quantian-general] Quantian and Java

[Simon Urbanek]

Hi Dirk,

On Mar 18, 2006, at 10:46 PM, Dirk Eddelbuettel wrote:

> | But I am having a problem with the rJava library for R (needed  
> for JGR)
> | in Quantian_0.7.9.2. It seems to be a Java problem. I do library 
> (JGR) or
> | library(rJava) and get:
> |
> | Error in dyn.load ...
> | unable to load ... rJava.so
> | libjvm.so: cannot open shared object file: No such file or directory
>
> I noticed that too post-release.  However, the good news is that  
> this seems
> to happen only when you start R directly, or via ESS, and can be  
> circumvented
> (see below).  I suspect that because nobody tells R (at run-time)  
> where the
> Java libraries are, libjvw.so is not found.
>

It seems as if your R build is not Java-aware. All necessary paths  
are set in the R script, so it works both in the shell and ESS if  
compiled properly. R uses the same mechanism as rJava so you should  
see the same output at configure time of R (i.e. whether Java support  
is enabled and where Java lives). My guess is that you compiled R  
before having Java installed and thus R didn't know about Java at  
that time. In that case, you have to set LD_LIBRARY_PATH manually (it  
still helps to run the configure script of R or JRI to see what the  
correct path is).

The whole issue is quite messy, because Sun's Java moves around with  
updates. We are working on a better solution that will allow you to  
run something like `R CMD java-configure' to update the paths in an  
already installed R - it will hopefully make it to the R 2.3 release.

Cheers,
Simon