kbenoit/quanteda: CRAN release v0.99

New features

• Improvements and consoldiation of methods for detecting multi-word expressions, now active only through textstat_collocations(), which computes only the lambda method for now, but does so accurately and efficiently. (#753, #803). This function is still under development and likely to change further.
• Added new quanteda_options that affect the maximum documents and features displayed by the dfm print method (#756).
• ngram formation is now significantly faster, including with skips (skipgrams).
• Improvements to topfeatures():
  • now accepts a groups argument that can be used to generate lists of top (or bottom) features in a group of texts, including by document (#336).
  • new argument scheme that takes the default of (frequency) "count" but also a new "docfreq" value (#408).
• New wrapper phrase() converts whitespace-separated multi-word patterns into a list of patterns. This affects the feature/pattern matching in tokens/dfm_select/remove, tokens_compound, tokens/dfm_lookup, and kwic. phrase() and the associated changes also make the behaviour of using character vectors, lists of characters, dictionaries, and collocation objects for pattern matches far more consistent. (See #820, #787, #740, #837, #836, #838)
• corpus.Corpus() for creating a corpus from a tm Corpus now works with more complex objects that include document-level variables, such as data from the manifestoR package (#849).
• New plot function textplot_keyness() plots term "keyness", the association of words with contrasting classes as measured by textstat_keyness().
• Added corpus constructor for corpus objects (#690).
• Added dictionary constructor for dictionary objects (#690).
• Added a tokens constructor for tokens objects (#690), including updates to tokens() that improve the consistency and efficiency of the tokenization.
• Added new quanteda_options(): language_stemmer and language_stopwords, now used for default in *_wordstem functions and stopwords() for defaults, respectively. Also uses this option in dfm() when stem = TRUE, rather than hard-wiring in the "english" stemmer (#386).
• Added a new function textstat_frequency() to compile feature frequencies, possibly by groups. (#825)
• Added nomatch option to tokens_lookup() and dfm_lookup(), to provide tokens or feature counts for categories not matched to any dictionary key. (#496)

• The functions sequences() and collocations() have been removed and replaced by textstat_collocations().
• (Finally) we added "will" to the list of English stopwords (#818).
• dfm objects with one or both dimensions haveing zero length, and empty kwic objects now display more appropriately in their print methods (per #811).
• Pattern matches are now implemented more consistently across functions. In functions such as *_select, *_remove, tokens_compound, features has been replaced by pattern, and in kwic, keywords has been replaced by pattern. These all behave consistently with respect to pattern, which now has a unified single help page and parameter description.(#839) See also above new features related to phrase().
• We have improved the performance of the C++ routines that handle many of the tokens_* functions using hashed tokens, making some of them 10x faster (#853).
• Upgrades to the dfm_group() function now allow "empty" documents to be created using the fill = TRUE option, for making documents conform to a selection (similar to how dfm_select() works for features, when supplied a dfm as the pattern argument). The groups argument now behaves consistently across the functions where it is used. (#854)
• dictionary() now requires its main argument to be a list, not a series of elements that can be used to build a list.
• Some changes to the behaviour of tokens() have improved the behaviour of remove_hyphens = FALSE, which now behaves more correctly regardless of the setting of remove_punct (#887).
• Improved cbind.dfm() function allows cbinding vectors, matrixes, and (recyclable) scalars to dfm objects.

• For the underlying methods behind textstat_collocations(), we corrected the word matching, and lambda and z calculation methods, which were slightly incorrect before. We also removed the chi2, G2, and pmi statistics, because these were incorrectly calculated for size > 2.
• LIWC-formatted dictionary import now robust to assignment to term assignment to missing categories.
• textmodel_NB(x, y, distribution = "Bernoulli") was previously inactive even when this option was set. It has now been fully implemented and tested (#776, #780).
• Separators including rare spacing characters are now handled more robustly by the remove_separators argument in tokens(). See #796.
• Improved memory usage when computing ntoken() and ntype(). (#795)
• Improvements to quanteda_options() now does not throw an error when quanteda functions are called directly without attaching the package. In addition, quanteda options can be set now in .Rprofile and will not be overwritten when the options initialization takes place when attaching the package.
• Fixed a bug in textstat_readability() that wrongly computed the number of words with fewer than 3 syllables in a text; this affected the FOG.NRI and the Linsear.Write measures only.
• Fixed mistakes in the computation of two docfreq schemes: "logave" and "inverseprob".
• Fixed a bug in the handling of multi-thread options where the settings using quanteda_options() did not actually set the number of threads. In addition, we fixed a bug causing threading to be turned off on macOS (due to a check for a gcc version that is not used for compiling the macOS binaries) prevented multi-threading from being used at all on that platform.
• Fixed a bug causing failure when functions that use quanteda_options() are called without the namespace or package being attached or loaded (#864).
• Fixed a bug in overloading the View method that caused all named objects in the RStudio/Source pane to be named "x". (#893)