I have an Ubuntu Quantal 12.10 Server 64-bit instance. I am using openNLP
for POS Tagging of sentences.

I am using POS tagging using openNLP with “Parallel Lapply setup”. It is
running fine in RStudio environment. But in Ubuntu environment it is
showing the following error.



*Error in do.call(c, clusterApply(cl, x = splitList(X, length(cl)), fun =
lapply,  :*

*  second argument must be a list*


Any suggestion for the problem I’m facing?



This is the code that I am using:



tagPOS <-  function(x, ...) {

    s <- as.String(x)

    word_token_annotator <- Maxent_Word_Token_Annotator()

    a2 <- Annotation(1L, "sentence", 1L, nchar(s))

    a2 <- annotate(s, word_token_annotator, a2)

    a3 <- annotate(s, PTA, a2)

    a3w <- a3[a3$type == "word"]

    POStags <- unlist(lapply(a3w$features, `[[`, "POS"))

    POStagged <- paste(sprintf("%s/%s", s[a3w], POStags), collapse = " ")

    list(POStagged = POStagged, POStags = POStags)

  }



  cl <- makeCluster(mc <- getOption("cl.cores", detectCores()/2))

  clusterEvalQ(cl, {

    library(openNLP)

    library(NLP)

    PTA <- Maxent_POS_Tag_Annotator()

  })



This is the setup I am using:

· Created an cloud instance with "Ubuntu Quantal 12.10 Server 64-bit
instance"



· Installed LAMP server in the instance



· After which I installed R. By default R version was 2.15.0



· Upgraded the R version to R 3.0.1

-- 
Regards,

Siddharth Arun,
Contact No. - +91 8880065278

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