Big Text Corpus打破了tm_map

在过去的几天里,我一直在打破这个.我搜索了所有的SO档案,并尝试了建议的解决方案,但似乎无法让这个工作.我在诸如2000 06,1995 -99等文件夹中有一组txt文档,并且想要运行一些基本的文本挖掘操作,例如创建文档术语矩阵和术语文档矩阵以及基于单词的共同位置进行一些操作.我的脚本适用于较小的语料库,但是,当我使用更大的语料库进行尝试时,它会让我失望.我已经粘贴了一个这样的文件夹操作的代码.

library(tm) # Framework for text mining.
library(SnowballC) # Provides wordStem() for stemming.
library(RColorBrewer) # Generate palette of colours for plots.
library(ggplot2) # Plot word frequencies.
library(magrittr)
library(Rgraphviz)
library(directlabels)

setwd("/ConvertedText")
txt <- file.path("2000 -06")

docs<-VCorpus(DirSource(txt,encoding = "UTF-8"),readerControl = list(language = "UTF-8"))
docs <- tm_map(docs,content_transformer(tolower),mc.cores=1)
docs <- tm_map(docs,removeNumbers,removePunctuation,stripWhitespace,removeWords,stopwords("SMART"),stopwords("en"),mc.cores=1)
#corpus creation complete

setwd("/ConvertedText/output")
dtm<-DocumentTermMatrix(docs)
tdm<-TermDocumentMatrix(docs)
m<-as.matrix(dtm)
write.csv(m,file="dtm.csv")
dtms<-removeSparseTerms(dtm,0.2)
m1<-as.matrix(dtms)
write.csv(m1,file="dtms.csv")
# matrix creation/storage complete

freq <- sort(colSums(as.matrix(dtm)),decreasing=TRUE)
wf <- data.frame(word=names(freq),freq=freq)
freq[1:50]
#adjust freq score in next line
p <- ggplot(subset(wf,freq>100),aes(word,freq))+ geom_bar(stat="identity")+ theme(axis.text.x=element_text(angle=45,hjust=1))
ggsave("frequency2000-06.png",height=12,width=17,dpi=72)
# frequency graph generated


x<-as.matrix(findFreqTerms(dtm,lowfreq=1000))
write.csv(x,file="freqterms00-06.csv")
png("correlation2000-06.png",width=12,units="in",res=900)
graph.par(list(edges=list(col="lightblue",lty="solid",lwd=0.3)))
graph.par(list(nodes=list(col="darkgreen",lty="dotted",lwd=2,fontsize=50)))
plot(dtm,terms=findFreqTerms(dtm,lowfreq=1000)[1:50],corThreshold=0.7)
dev.off()

当我在tm_map中使用mc.cores = 1参数时,操作将无限期地继续.但是,如果我在tm_map中使用lazy = TRUE参数,它看似顺利,但后续操作会出现此错误.

Error in UseMethod("meta",x) : 
  no applicable method for 'meta' applied to an object of class "try-error"
In addition: Warning messages:
1: In mclapply(x$content[i],function(d) tm_reduce(d,x$lazy$maps)) :
  all scheduled cores encountered errors in user code
2: In mclapply(unname(content(x)),termFreq,control) :
  all scheduled cores encountered errors in user code

我一直在寻找一个解决方案,但一直都失败了.任何帮助将不胜感激！

最好！
?

R version 3.1.2 (2014-10-31)
Platform: x86_64-apple-darwin13.4.0 (64-bit)

locale:
[1] de_DE.UTF-8/de_DE.UTF-8/de_DE.UTF-8/C/de_DE.UTF-8/de_DE.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] snowfall_1.84-6    snow_0.3-13        Snowball_0.0-11    RWekajars_3.7.11-1 rJava_0.9-6              RWeka_0.4-23      
[7] slam_0.1-32        SnowballC_0.5.1    tm_0.6             NLP_0.1-5          twitteR_1.1.8      devtools_1.6      

loaded via a namespace (and not attached):
[1] bit_1.1-12     bit64_0.9-4    grid_3.1.2     httr_0.5       parallel_3.1.2 RCurl_1.95-4.3    rjson_0.2.14   stringr_0.6.2 
[9] tools_3.1.2

MyCorpus <- tm_map(MyCorpus,content_transformer(function(x) iconv(x,to='UTF-8-MAC',sub='byte')),mc.cores=1)