无法让 tm_map 使用 mc.cores 参数

unable to get tm_map to use mc.cores argument

我有一个包含超过 10M 文档的大型语料库。每当我尝试使用 mc.cores 参数对多个内核进行转换时,我都会收到错误消息:

Error in FUN(content(x), ...) : unused argument (mc.cores = 10)

我当前托管的 r studio 中有 15 个可用内核。

# I have a corpus
> inspect(corpus[1])
<<VCorpus>>
Metadata:  corpus specific: 0, document level (indexed): 0
Content:  documents: 1

[[1]]
<<PlainTextDocument>>
Metadata:  7
Content:  chars: 46

> length(corpus)
[1] 10255313

观察当我尝试使用 tm_map

进行转换时会发生什么
library(tidyverse)
library(qdap)
library(stringr)
library(tm)
library(textstem)
library(stringi)
library(SnowballC)

例如

> corpus <- tm_map(corpus, content_transformer(replace_abbreviation), mc.cores = 10)
Error in FUN(content(x), ...) : unused argument (mc.cores = 10)

尝试添加 lazy = T

corpus <- tm_map(corpus, content_transformer(replace_abbreviation), mc.cores = 10, lazy = T) # read the documentation, still don't really get what this does

改造后如果我去例如

> corpus[[1]][1] I get:
Error in FUN(content(x), ...) : unused argument (mc.cores = 10)

而之前我会得到:

> corpus.beforetransformation[[1]][1]
$content
[1] "here is some text"

我在这里做错了什么?我如何使用 mc.cores 参数来使用我的更多处理器?

可重现的例子:

sometext <- c("cats dogs rabbits", "oranges banannas pears", "summer fall winter") %>% 
  data.frame(stringsAsFactors = F) %>% DataframeSource %>% VCorpus

corpus.example <- tm_map(sometext, content_transformer(replace_abbreviation), mc.cores = 2, lazy = T)
corpus.example[[1]][1]

来自 tm documentation,尝试以下操作:

options(mc.cores = 10)  # or whatever
tm_parLapply_engine(parallel::mclapply)  # mclapply gets the number of cores from global options
tm_map(sometext, content_transformer(replace_abbreviation))