This is a Java error inside Weka, so R-help is hardly an appropriate list.
RWeka supplies a version of Weka, and you already have one on your
classpath. I suspect a mismatch, so try not having Weka in your
classpath. (I would have expected the RWeka version to take precedence,
but as I cannot run RWeka on this machine (the AMD64 version of rJava does
not work enough), I cannot check.)
On Fri, 3 Mar 2006, Derek White wrote:
> Hello all,
>
> I am attempting to run an R script that makes use of RWeka. I am
> running SuSE Linux 9.3 with Java 1.5.0_06, R version 2.2.1, Weka
> 3-4-7, and Rweka 0.2-1.
>
> CLASSPATH="/usr/local/weka-3-4-7/weka.jar:/usr/local/JGR/JGR.jar"
>
> I receive the error:
>
>
NewObject("weka/core/Instances","(Ljava/io/Reader;)V",...)
failed
> Exception in thread "main" java.io.IOException: end of line
expected,
> read Token[=], line 1
> at weka.core.Instances.errms(Unknown Source)
> at weka.core.Instances.getLastToken(Unknown Source)
> at weka.core.Instances.readHeader(Unknown Source)
> at weka.core.Instances.<init>(Unknown Source)
> Error in validObject(.Object) : invalid class "jobjRef" object:
> invalid object for slot "jobj" in class "jobjRef": got
class "NULL",
> should be or extend class "externalptr"
> In addition: Warning message:
> Unable to create object of the class weka/core/Instances , returning
> null reference. in: .jnew("weka/core/Instances", .jcast(reader,
> "java/io/Reader"))
> Execution halted
>
>
> My R script seems to run fine on Windows XP.
>
> Thanks in advance,
> Derek
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html
>
--
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595