NEWS

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rsubgroup 1.1 (2021-02-23)

• provide automatic discretization options of VIKAMINE kernel for numeric attributes, they are internally discretized SDTaskConfig provides new options. defaults: discretize = TRUE, nbins = 3
• Improved/extended tests for this.

rsubgroup 1.0 (2020-04-22)

• internal enhancements in subgroup.jar, i.e., the VIKAMINE kernel library, e.g. according to better error messages relating to the R connection.
• Improved documentation and examples.

rsubgroup 0.9 (2020-03-04)

• internal enhancements in subgroup.jar, i.e., the VIKAMINE kernel library
• rsubgroup requires >= Java 8 (i.e., >= java.version 1.8)

rsubgroup 0.8

• Improvements
• included new SDTaskConfig#parfilter: Provides the minimal improvement value for the postfilter (for min-improve-* filters), or the applied significance level (P) for sig-improve-* filters.
• updated org.vikamine.kernel version
• package-internal: fixed Java requirements (string) in DESCRIPTION
• Bug fixes.
• fixed bug in automatic discretization used in rsubgroup VIKAMINE kernel

rsubgroup 0.7

• Improvements
• document setting Java heap space before loading the rsubgroup library.
• Improve error handling (exception signaling) when running subgroup discovery using an ARFF file directly.
• SDTaskConfig now provides an option mintp, that allows to set the minimal true positives threshold to be contained in a subgroup, which is usually very effective for pruning.
• The Pattern class now contains a list of selection expressions (selectors) for the subgroup, not only the description. Using the is.pattern.matching function, a match of a pattern and a data instance can be checked now.
• In SDTaskConfig, postfilter can be a single filter or a vector of filters, that are then applied in order on the results. This allows e.g., the combination of minimal improvement filtering with weighted covering post-processing.
• Implement/enable new quality function (Adjusted residuals, cf. Agresti 2007) ==> qf="ares"
• For a binary target variable, the resulting patterns now also store the chi-squared value comparing subgroup and population w.r.t. the target in the parameters field.
• ToDataFrame shows the chi-squared value for a binary target.
• Bug fixes:
• fix providing attributes=NULL (i.e., automatically include all attributes) into subgroup discovery
• fix max-attribute-value bug in SGSelectorGenerator, causing the inclusion of two few selectors in subgroup discovery methods

rsubgroup 0.6 (2014-09-11)

• Improvements:
• optimizations in the beam search algorithm
• significant memory optimization (dataset storage, access)
• ARFF: enable import of "empty" attributes, i.e., with an empty value domain (this can occur, for example, when importing columns with only 'NA' in R)
• Bug fixes:
• exclude target from subgroup attributes
• fix loading of ARFF file, for attributes/values with trailing spaces