R tm package vcorpus: Error in converting corpus to data frame
I am using the tm
package to clean up some data using the following code:
mycorpus <- Corpus(VectorSource(x))
mycorpus <- tm_map(mycorpus, removePunctuation)
I then want to convert the corpus back into a data frame in order to export a text file that contains the data in the original format of a data frame. I have tried the following:
dataframe <- as.data.frame(mycorpus)
But this returns an error:
"Error in as.data.frame.default.(mycorpus) : cannot coerce class "c(vcorpus, > corpus")" to a data.frame
How can I convert a corpus into a data frame?
Your corpus is really just a character vector with some extra attributes. So it's best to convert it to character, then you can save that to a data.frame like so:
library(tm)
x <- c("Hello. Sir!","Tacos? On Tuesday?!?")
mycorpus <- Corpus(VectorSource(x))
mycorpus <- tm_map(mycorpus, removePunctuation)
dataframe <- data.frame(text=unlist(sapply(mycorpus, `[`, "content")),
stringsAsFactors=F)
which returns
text
1 Hello Sir
2 Tacos On Tuesday
UPDATE: With newer version of tm
, they seem to have updated the as.list.SimpleCorpus
method which really messes with using sapply
and lapply
. Now I guess you'd have to use
dataframe <- data.frame(text=sapply(mycorpus, identity),
stringsAsFactors=F)
The Corpus classed objected has a content
attribute accessible through get
:
library("tm")
x <- c("Hello. Sir!","Tacos? On Tuesday?!?")
mycorpus <- Corpus(VectorSource(x))
mycorpus <- tm_map(mycorpus, removePunctuation)
attributes(mycorpus)
# $names
# [1] "content" "meta" "dmeta"
#
# $class
# [1] "SimpleCorpus" "Corpus"
#
df <- data.frame(text = get("content", mycorpus))
head(df)
# text
# 1 Hello Sir
# 2 Tacos On Tuesday
The older answer posted by MrFlick works only in previous version on tm, I was able to fix it by removing content from the formula.
dataframe<-data.frame(text=unlist(sapply(mycorpus, `[`)), stringsAsFactors=F)