Library for corpus analysis using the Corpus Workbench as an efficient back end for indexing and querying large corpora. The package offers functionality to flexibly create partitions and to carry out basic statistical operations (count, co-occurrences etc.). The original full text of documents can be reconstructed and inspected at any time. Beyond that, the package is intended to serve as an interface to packages implementing advanced statistical procedures. Respective data structures (document term matrices, term co- occurrence matrices etc.) can be created based on the indexed corpora.
Purpose: The focus of the package ‘polmineR’ is the interactive analysis of corpora using R. Core objectives for the development of the package are performance, usability, and a modular design.
Aims: Key aims for developing the package are:
To keep the original text accessible. A seamless integration of qualitative and quantitative steps in corpus analysis supports validation, based on inspecting the text behind the numbers.
To provide a library with standard tasks. It is an open source platform that will make text mining more productive, avoiding prohibitive costs to reimplement basics, or to run many lines of code to perform a basic tasks.
To create a package that makes the creation and analysis of subcorpora (‘partitions’) easy. A particular strength of the package is to support contrastive/comparative research.
To offer performance for users with a standard infrastructure. The package picks up the idea of a three-tier software design. Corpus data are managed and indexed by using the Open Corpus Workbench (CWB). The CWB is particularly efficient for storing large corpora and offers a powerful language for querying corpora, the Corpus Query Processor (CQP).
To support sharing consolidated and documented data, following the ideas of reproducible research.
Background: The polmineR-package was specifically developed to make full use of the XML annotation structure of the corpora created in the PolMine project (see polmine.sowi.uni-due.de). The core PolMine corpora are corpora of plenary protocols. In these corpora, speakers, parties etc. are structurally annotated. The polmineR-package is meant to help making full use of the rich annotation structure.
Upon loading polmineR, a message will report the version of the package and the location of a so-called ‘registry’-directory.
library(polmineR)#> polmineR v0.7.10.9001#> session registry: /private/var/folders/r6/1k6mxnbj5077980k11xvr0q40000gn/T/Rtmpe923aa/polmineR_registry
The session registry directory is populated with files that describe the corpora that are present and accessible on the user’s system.
Indexed corpora wrapped into R data packages can be installed from a (private) package repository.
install.packages("GermaParl", repos = "")install.packages("europarl.en", repos = "")
use()-function will activate a corpus included in a data
package. The registry files describing the corpora in a package are
added to the session registry directory.
use("europarl.en") # activate the corpus in the europarl-en package#> ... activating corpus: europarl-en
An advantage of keeping corpora in data packages are the versioning and documentation mechanisms that are the hallmark of packages. Of course, polmineR will work with the library of CWB indexed corpora stored on your machine. The corpora described in the registry directory defined by the environment variable CORPUS_REGISTRY will be added to the session registry directory when loading polmineR.
All methods can be applied to a whole corpus, as well as to partitions (i.e. subcorpora). Use the metadata of a corpus (so-called s-attributes) to define a subcorpus.
ep2005 <- partition("EUROPARL-EN", text_year = "2006")#> ... get encoding: latin1#> ... get cpos and strucssize(ep2005)#>  3100529
barroso <- partition("EUROPARL-EN", speaker_name = "Barroso", regex = TRUE)#> ... get encoding: latin1#> ... get cpos and strucssize(barroso)#>  98142
Partitions can be bundled into partition_bundle objects, and most methods can be applied to a whole corpus, a partition, or a partition_bundle object alike. Consult the package vignette to learn more.
Counting occurrences of a feature in a corpus, a partition or in the partitions of a partition_bundle is a basic operation. By offering access to the query syntax of the Corpus Query Processor (CQP), polmineR package exposes a query syntax that goes far beyond regular expressions. See the CQP documentation to learn more.
count("EUROPARL-EN", "France")#> query count freq#> 1: France 5517 0.0001399122count("EUROPARL-EN", c("France", "Germany", "Britain", "Spain", "Italy", "Denmark", "Poland"))#> query count freq#> 1: France 5517 1.399122e-04#> 2: Germany 4196 1.064114e-04#> 3: Britain 1708 4.331523e-05#> 4: Spain 3378 8.566676e-05#> 5: Italy 3209 8.138089e-05#> 6: Denmark 1615 4.095673e-05#> 7: Poland 1820 4.615557e-05count("EUROPARL-EN", '"[pP]opulism"')#> query count freq#> 1: "[pP]opulism" 107 2.713542e-06
The dispersion method is there to analyse the dispersion of a query, or a set of queries across one or two dimensions (absolute and relative frequencies). The CQP syntax can be used.
populism <- dispersion("EUROPARL-EN", "populism", s_Attribute = "text_year", progress = FALSE)popRegex <- dispersion("EUROPARL-EN", '"[pP]opulism"', s_attribute = "text_year", cqp = TRUE, progress = FALSE)
The cooccurrences method is used to analyse the context of a query (including some statistics).
islam <- cooccurrences("EUROPARL-EN", query = 'Islam', left = 10, right = 10)islam <- subset(islam, rank_ll <= 100)dotplot(islam)islam
Compare partitions to identify features / keywords (using statistical tests such as chi square).
ep2002 <- partition("EUROPARL-EN", text_year = "2002", p_attribute = "word")epPre911 <- partition("EUROPARL-EN", text_year = 1997:2001, p_attribute = "word")y <- features(ep2002, epPre911, included = FALSE)
So what happens in the context of a word, or a CQP query? To attain valid research results, reading will often be necessary. The kwic method will help, and uses the conveniences of DataTables, outputted in the Viewer pane of RStudio.
kwic("EUROPARL-EN", "Islam", meta = c("text_date", "speaker_name"))
Corpus analysis involves moving from text to numbers, and back again. Use the read method, to inspect the full text of a partition (a speech given by chancellor Angela Merkel in this case).
use("GermaParl")merkel <- partition("GERMAPARL", speaker = "Angela Merkel", date = "2013-09-03")read(merkel)
Many advanced methods in text mining require term document matrices as input. Based on the metadata of a corpus, these data structures can be obtained in a fast and flexible manner, for performing topic modelling, machine learning etc.
use("europarl.en")speakers <- partition_bundle("EUROPARL-EN", s_attribute = "speaker_id",progress = FALSE, verbose = FALSE)speakers_count <- count(speakers, p_attribute = "word", progress = TRUE)tdm <- as.TermDocumentMatrix(speakers_count, col = "count")dim(tdm)
The CRAN release of polmineR can be installed using
install.packages(), all dependencies will be installed, too.
To install the most recent development version that is hosted in a GitHub repository, use the installation mechanism offered by the devtools package.
install.packages("devtools")devtools::install_github("PolMine/polmineR", ref = "dev")
Check the installation by loading polmineR and activating the corpora included in the package.
The following instructions for Mac users assume that R is installed on your system. Binaries are available from the Homepage of the R Project. An installation of RStudio is highly recommended. Get the Open Source License version of RStudio Desktop.
At this stage, the RcppCWB dependency is not available as a pre-compiled binary and needs to be compiled. A set of system requirements needs to be fulfilled to do this.
First, you will need an installation of Xcode, which you can get it via the Mac App Store. You will also need the Command Line Tools for Xcode. It can be installed from a terminal with:
Please make sure that you agree to the license.
Second, an installation of XQuartz is required. It can be obtained from www.xquartz.org.
Third, to fulfill the system requirements of the RcppCWB package, the Glib and pcre libraries need to be installed. Using a package manager makes things considerably easier. We recommend using ‘Homebrew’. To install Homebrew, follow the instructions on the Homebrew Homepage. The following commands then need to be executed from a terminal window. They will install the C libraries that the RcppCWB package relies on:
brew -v install pkg-configbrew -v install glib --universalbrew -v install pcre --universalbrew -v install readline
The latest release of polmineR can be installed from CRAN using the
The development version of polmineR can be installed using devtools:
install.packages("devtools") # unless devtools is already installeddevtools::install_github("PolMine/polmineR", ref = "dev")
Check whether everything works by loading polmineR, and activating the demo corpora included in the package.
If you have not yet installed R on your Ubuntu machine, there is a good instruction at ubuntuuser. To install base R, enter in the terminal.
sudo apt-get install r-base r-recommended
Make sure that you have installed the latest version of R. The following commands will add the R repository to the package sources and run an update. The second line assumes that you are using Ubuntu 16.04.
sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com E084DAB9sudo add-apt-repository 'deb xenial/'sudo apt-get updatesudo apt-get upgrade
It is highly recommended to install RStudio, a powerful IDE for R. Output of polmineR methods is generally optimized to be displayed using RStudio facilities. If you are working on a remote server, running RStudio Server may be an interesting option to consider.
The RcppCWB package, the interface used by polmineR to query CWB corpora, will require the pcre, glib and pkg-config libraries. They can be installed as follows. In addition libxml2 is installed, a dependency of the R package xml2 that is used for manipulating html output.
sudo apt-get install libglib2.0-dev libssl-dev libcurl4-openssl-devsudo apt-get install libxml2-devsudo apt-get install libprotobuf-dev
The system requirements will now be fulfilled. From R, install dependencies for rcqp/polmineR first, and then rcqp and polmineR.
Use devtools to install the development version of polmineR from GitHub.
install.packages("devtools")devtools::install_github("PolMine/polmineR", ref = "dev")
You may want to install packaged corpora to run examples in the vignette, and the man packages.
To have access to all package functions and to run all package tests, the installation of further system requirements and packages is required. The xlsx dependency requires that rJava is installed and configured for R. That is done on the shell:
sudo apt-get install openjdk-8-jresudo R CMD javareconf
To run package tests including (re-)building the manual and vignettes, a working installation of Latex is required, too. Be aware that this may be a time-consuming operation.
sudo apt-get install texlive-full texlive-xetex
Now install the remaining packages from within R.
install.packages(pkgs = c("rJava", "xlsx", "tidytext"))
use-function is limited now to activating the corpus in data packages. Having introduced the session registry, switching registry directories is not needed any more.
context-objects has been reworked entirely (and is working again); a new
context-objects has been introduced. Buth steps are intended for workflows for dictionary-based sentiment analysis.
partition-class objects is introduced. If the Object has been weighed, the list that is returned will include a report on weights.
partition_bundle-class, rather than inheriting from
bundle-class directly, will now inherit from the
weigh-method is now implemented for the classes
count_bundle. Via inheritance, it will also be available for
partition_bundle. Useful for dictionary-based sentiment analysis, for instance. There is an example that explains the workflow.
as.regions-function has been turned into a
as.regions-method to have a more generic tool.
size_coi-slot of the
context-object included the node; the node (i.e. matches for queries) is excluded now from the count of the size_coi.
context-method, so that full use of data.table speeds up things.
highlight-method allows definitions of terms to be highlighted to be passed in via three dots (...); no explicit list necessary.
highlight-method implemented now for class
use(), the registry directory is reset for CQP, so that the new corpus is available for using it with CQP syntax.
html()-method will allow to define a scroll box. Useful to embed a fulltext output to a Rmarkdown document.
knit_print()-method for textstat- and kwic-objects, to offer a seamless inclusion of analyses in Rmarkdown documents.
xtermStyle used for kwic output on console
partition object can be indexed
partition.init expanded to allow for the generation of partitions with specified start and end dates
wordscore analysis adapted so that it can be really used for performing wordscore analysis