[R] Import R-output into Java

Romain Francois romain.francois at dbmail.com
Thu Mar 19 16:20:15 CET 2009


Maxl18 wrote:
> Hello,
> I want to import R-output via Rserve to Java, especially for the function
> ctree from the package party.
> Rserve is working properly.
>
> Yet, I only get the predictions with the Java code
>
>    try{
>        RConnection c = new RConnection();
>        ...
>        c.voidEval("modell <- ctree(...)");
>        REXP y = c.eval("nodes(modell,1)[[1]]$prediction");
>        ...
>    }catch(Exception e){}
>
> When I try to get the whole text with
>
>    REXP z = c.eval("nodes(modell,1)[[1]]");
>    System.out.println(z);
>
> I get something like   
> org.rosuda.REngine.REXPGenericVector at 119c082+[10]named
>
> But I want the text which is printed in R.
>
> What can I do?
> Thanks, Max
>
>
> Once again:
> It`s clear to get the result in R but I don`t know hoe to get the R-output
> into Java (or into a file, i.e. .txt)
>   
This is what the toString method from REXP returns, you need use other 
REXP methods to extract what you are looking for:
http://rforge.net/Rserve/doc/org/rosuda/REngine/REXP.html#asStrings()

Romain

-- 
Romain Francois
Independent R Consultant
+33(0) 6 28 91 30 30
http://romainfrancois.blog.free.fr




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