[R] Java related (?) problems with RWeka

[Derek White]

Prof. Ripley,

It behaves the same with or without weka in the CLASSPATH.  I will  
ask the Weka people, thank you for the suggestion.

Derek


On Mar 4, 2006, at 2:02 AM, Prof Brian Ripley wrote:

> 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
>>
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>>
>
> -- 
> 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