Bugfixes:

- Fixes required by the new version of Matrix and the new use of HTML Tidy in R 4.2.

Enhancements:

- The user can control the number of decimal digits when exporting to LaTeX or when printing formal contexts, concept lattices and implications. Just use fcaR_options(decimal_places = n), where n is the number of desired decimal digits.

New functionality:

- Now the package uses the
*settings*package to manage several options. Currently, the only option is the number of decimal digits to use when printing or exporting to LaTeX.

Bugfixes:

- Fixed exporting to latex with special characters such as $, _, etc.

Enhancements:

- Better printing of Sets.
- More optimized ConceptLattice class. Now it inherits from a ConceptSet superclass with generic functions.

New functionality:

- Added function to compute the
**difference**of two Sets. - Added function to compute the
**dual**of a FormalContext. - Now one can create a FormalContext from a CSV, CXT or RDS file directly, without needing to “load()” it.
- FormalContexts can now be saved to CXT format, in addition to RDS.
- Added functions to compute the top and the bottom of a concept lattice.
- Added new function sub() to extract a single Concept from a ConceptSet.
- Added functions %holds_in% and %respects%, which check the
**validity**of a set of implications in a formal context, and if a list of attribute sets respect an implication set. - Added functions %entails% and %~% to check the
**entailment**and**equivalence**between two implication sets. - Added new convenience function to map attributes between Sets, so computing intents, extents and closures is more robust.
- Added new functions
`%&%`

and`%|%`

that compute the intersection (logical*and*) and the union (*or*operation) on Sets. **Conceptual scaling**, including nominal, ordinal, interordinal, biordinal and interval scales for many-valued formal contexts. Also, computation of background knowledge from the applied scales and of the implications that hold in the formal context. Added new vignette.

*Breaking changes*:

- The former SparseSet and SparseConcept classes are now named Set and Concept. Thus, to create an object of these types, just use Set$new(…) or Concept$new(…). Analogously, the former function as_SparseSet() is now as_Set().

Bugfixes:

- Minor bugfixes in several functions.

Bugfixes:

- Minor bugfixes in several functions.
- Fixed C source that could generate some problems.

Enhancements:

- Reduced number of dependencies.
- Better printing of FormalContexts, specially for binary FormalContexts.

Bugfixes:

- Detect if R has been built with no long double capabilities and warn the user if she tries to plot FormalContexts and ConceptLattices.

Bugfixes:

- Fixes #17. The reduced set of implications after performing closure with reduce == TRUE now stores the matrix I, so it can be re-exported to the arules format.

Enhancements:

- More efficient version of the simplification rule. Now it performs linearly on the number of implications.
- Added a way to extend the equivalence rules by means of the registry package. This has been used to introduce the “Right Simplification” and the “Reorder” rules.
- New vignette to show how to extend equivalence rules in the package.
- More efficient version of the NextClosure algorithm to mine concepts and implications.

Bugfixes:

- Fixes #15. A problem with version 1.6-6 of arules.
- Bugfix when using the trivial context (S, S, !=)
- Several bugfixes in LaTeX output.

Enhancements:

- Added export of plots to TiKZ to be included in LaTeX documents.
- Faster computation of concepts and implications.
- Added new function to decompose a concept in its irreducible components.
- Added function to compute the canonical basis from an ImplicationSet.

- Changes to some C functions since they could potentially give a segfault.

- Made minor changes in the DESCRIPTION.

Made changes suggested by CRAN:

- Added examples in the documentation.
- Changed cat() to message() in functions not related to printing.
- Added proper contributors.

Updated vignettes

- Added a
`NEWS.md`

file to track changes to the package.