[英]Big Text Corpus breaks tm_map
I have been breaking my head over this one over the last few days. 在过去的几天里,我一直在打破这个。 I searched all the SO archives and tried the suggested solutions but just can't seem to get this to work.
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。 I have sets of txt documents in folders such as 2000 06, 1995 -99 etc, and want to run some basic text mining operations such as creating document term matrix and term document matrix and doing some operations based co-locations of words.
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。 My script works on a smaller corpus, however, when I try it with the bigger corpus, it fails me.
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。 I have pasted in the code for one such folder operation.
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, mc.cores=1)
docs <- tm_map(docs, removePunctuation, mc.cores=1)
docs <- tm_map(docs, stripWhitespace, mc.cores=1)
docs <- tm_map(docs, removeWords, stopwords("SMART"), mc.cores=1)
docs <- tm_map(docs, removeWords, 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, height=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()
When I use the mc.cores=1 argument in tm_map, the operation continues indefinitely. 当我在tm_map中使用mc.cores = 1参数时,操作将无限期地继续。 However, if I use the lazy=TRUE argument in tm_map, it seemingly goes well, but subsequent operations give this error.
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
I have been looking all over for a solution but have failed consistently. 我一直在寻找一个解决方案,但一直都失败了。 Any help would be greatly appreciated!
任何帮助将不胜感激!
Best! 最好! k
ķ
I found a solution that works. 我找到了一个有效的解决方案。
Background/Debugging Steps 背景/调试步骤
I tried several things that did not work: 我尝试了几件不起作用的东西:
While it isn't working for 2 of my scripts, it works every time for a third script. 虽然它不能用于我的两个脚本,但它每次都适用于第三个脚本。 But the code of all three scripts is the same only the size of the .rda file I am loading is different.
但是所有三个脚本的代码都是相同的,只是我加载的.rda文件的大小不同。 The data structure is also identical for all three.
这三种数据结构也相同。
Just weird. 太奇怪了。
My sessionInfo()
output: 我的
sessionInfo()
输出:
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
Solution 解
I just added this line after loading the data and everything works now: 我刚加载数据后添加了这一行,现在一切正常:
MyCorpus <- tm_map(MyCorpus,
content_transformer(function(x) iconv(x, to='UTF-8-MAC', sub='byte')),
mc.cores=1)
Found the hint here: http://davetang.org/muse/2013/04/06/using-the-r_twitter-package/ (The author has updated his code due to the error on November 26, 2014.) 在此处找到提示: http : //davetang.org/muse/2013/04/06/using-the-r_twitter-package/ (由于2014年11月26日的错误,作者更新了他的代码。)
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