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\name{tagsets}
\alias{Penn_Treebank_POS_tags}
\alias{Brown_POS_tags}
\alias{Universal_POS_tags}
\alias{Universal_POS_tags_map}
\title{NLP Tag Sets}
\description{
Tag sets frequently used in Natural Language Processing.
}
\usage{
Penn_Treebank_POS_tags
Brown_POS_tags
Universal_POS_tags
Universal_POS_tags_map
}
\details{
\code{Penn_Treebank_POS_tags} and \code{Brown_POS_tags} provide,
respectively, the Penn Treebank POS tags
(\url{https://catalog.ldc.upenn.edu/docs/LDC95T7/cl93.html}, Table 2)
and the POS tags used for the Brown corpus
(\url{https://en.wikipedia.org/wiki/Brown_Corpus}),
both as data frames with the following variables:
\describe{
\item{entry}{a character vector with the POS tags}
\item{description}{a character vector with short descriptions of the
tags}
\item{examples}{a character vector with examples for the tags}
}
\code{Universal_POS_tags} provides the universal POS tagset introduced
by Slav Petrov, Dipanjan Das, and Ryan McDonald
(\doi{10.48550/arXiv.1104.2086}), as a data frame with character
variables \code{entry} and \code{description}.
\code{Universal_POS_tags_map} is a named list of mappings from
language and treebank specific POS tagsets to the universal POS tags,
with elements named \samp{en-ptb} and \samp{en-brown} giving the
mappings, respectively, for the Penn Treebank and Brown POS tags.
}
\source{
\url{https://catalog.ldc.upenn.edu/docs/LDC95T7/cl93.html},
% As of 2024-07, \url{http://www.hit.uib.no/icame/brown/bcm.html} no
% longer works, so use the download info from Wikipedia.
\url{http://www.nltk.org/nltk_data/},
\url{https://github.com/slavpetrov/universal-pos-tags}.
}
\examples{
## Penn Treebank POS tags
dim(Penn_Treebank_POS_tags)
## Inspect first 20 entries:
write.dcf(head(Penn_Treebank_POS_tags, 20L))
## Brown POS tags
dim(Brown_POS_tags)
## Inspect first 20 entries:
write.dcf(head(Brown_POS_tags, 20L))
## Universal POS tags
Universal_POS_tags
## Available mappings to universal POS tags
names(Universal_POS_tags_map)
}
|
