NEWS.md
In GaussSuppression: Tabular Data Suppression using Gaussian Elimination

The Gaussian elimination secondary suppression algorithm has now been documented in a "Privacy in Statistical Databases 2024" paper.
The package description has been updated with this reference (Langsrud, 2024).
Due to updates in the SSBtools package (version 1.5.4), it is now meaningful to include NA’s in the grouping variables.
Note the parameter NAomit to SSBtools::Formula2ModelMatrix():
- When TRUE, NAs in the grouping variables are omitted in output and not included as a separate category.
- This parameter can be input to GaussSuppressionFromData() and its wrappers.
aggregateNA is new parameter to GaussSuppressionFromData():
- Whether to include NAs in the grouping variables while preAggregate/extraAggregate.
- Needs to be TRUE (default) to utilize the above NAomit parameter.
Due to updates in the SSBtools package (version 1.5.4), where data.table is now listed under Suggests, some functionality can be speeded up.
Set the new parameter aggregatePackage to "data.table" to utilize this possibility.
- aggregatePackage is parameter to GaussSuppressionFromData() and its wrappers.
- Also note the related new parameters aggregateBaseOrder and rowGroupsPackage.

A bug related to the remove0 parameter is now fixed
There was a bug related to the remove0 parameter in SuppressFewContributors/NContributorsRule introduced in version 0.8.0. When a single numVar was used as input, the remove0 functionality failed.

SuppressDominantCells() is now considered a common function for both the nk-dominance rule and the p-percent rule.
The pPercent parameter is now exposed in the SuppressDominantCells() documentation.
The n parameter in SuppressDominantCells() now defaults to 1:length(k).
To simplify common use.
A problem in experimental interval suppression is now fixed.
It was a bug occurring in cases where a response value of zero was secondary suppressed.
Improvements due to updates in the SSBtools package (version 1.5.2).
Fix for a rare problem in GaussSuppression(),
- Could happen with parallel eliminations combined with integer overflow. Then warning message: longer object length is not a multiple of shorter object length
Minor change to the singleton method "anySum" in GaussSuppression() to align with best theory.
- In practice, this rarely makes a difference.
- The previous behavior can be ensured by setting singletonMethod to either "anySumOld" or "anySumNOTprimaryOld".

Experimental functionality to meet interval width requirements has been incorporated
If at least one of the two parameters below is specified, in addition to the lpPackage parameter, further suppression will be performed to satisfy the interval width requirements.
- rangePercent: Required interval width expressed as a percentage
- rangeMin: Minimum required width of the interval

Improved singleton methods for magnitude tables
A new default setting, singletonMethod = "numttHTT", has been introduced in the wrappers SuppressDominantCells() and SuppressFewContribitors(). This setting represents the method that offers the highest level of protection. However, it should be noted that with this setting, the computational load of the suppression algorithm may double, which could potentially lead to a doubling of the execution time as well. During these computations, ":::" will be displayed instead of "....".
- To prevent this doubling, set singletonMethod = "numttHtT".
- The behavior of version 0.7.0 can be restored by setting singletonMethod = "numttH".
- A simpler and faster method is achievable with singletonMethod = "numttT".
- As in previous versions, singleton handling can be disabled by setting singletonMethod = "none".
Additional information can be found by ?SSBtools::NumSingleton.
Some explanation is provided at the bottom of the magnitude vignette.
This will later be documented in a more comprehensive manner (paper).
Improved functionality of the SuppressDominantCells() and SuppressFewContributors() wrappers.
Improved support for handling multiple numerical variables, introducing new parameters: dominanceVar and candidatesVar.
The removeCodes parameter is now also available in the DominanceRule() and SuppressDominantCells() functions.
Support for multiple contributorVar (charVar) in the SuppressFewContributors() and NContributorsRule() functions.
Now, SuppressDominantCells() includes special functionality to prevent zero cells, which have been suppressed, from being revealable in cases where negative values cannot occur. See the parameter singletonZeros.
The update described below enables the specification of the pPercent parameter directly through SuppressDominantCells().
The p% rule for magnitude tables has been implemented through the introduction of a new primary suppression function, PPercentRule().
Technically, PPercentRule() and DominanceRule() now serve as wrappers for the newly introduced. general function MagnitudeRule().
AdditionalSuppression() generalized to take a wrappers as input.
New special functions for the avoidance of suppression
PrimaryRemoveWg(), CandidatesNumWg() and ForcedWg()
Experimental functionality for interval calculations has been included
Intervals can now be calculated using the new function ComputeIntervals().
When the lpPackage parameter is specified in GaussSuppressionFromData() or in any of its wrappers, intervals for primary suppressed cells will be computed and included in the output.

More vignettes are included.
Better singleton handling for magnitude tables when using SuppressDominantCells() and SuppressFewContributors().
Due to improvements in the SSBtools package (version 1.4.6).
Due to new default extraAggregate = TRUE in the specs, dominanceSpec and fewContributorsSpec.
More default values are explicitly included in the in specs so that they are easier seen.
See PackageSpecs().

A vignette entitled "Defining Tables for GaussSuppression" is now included.
Now, easy-to-use wrapper functions are included.
SuppressSmallCounts(), SuppressDominantCells(), and SuppressFewContributors(), along with SuppressKDisclosure() (which was available in the previous version).
Built-in specs that contribute to a simpler interface have been adopted.
See PackageSpecs().
Sampling weights are now possible in the dominance rule.
See DominanceRule().
More advanced singleton handling that makes use of new functionality in the SSBtools package (version 1.4.4).
See SSBtools::GaussSuppression().
See SingletonUniqueContributor().
Now forced and usafe are possible output columns.
Where unsafe means unsafe primary suppressions due to forced cells. That, is the unsafe primarily suppressed values can be re-calculated from the values of the cells forced to be not suppressed.
See parameters forcedInOutput and unsafeInOutput to GaussSuppressionFromData().

Now the original variable names, as specified by freqVar and weightVar, are kept in the output.
In previous versions these names were standardized to "freq" and "weight".
Code relying on previous behavior with other freqVar/weightVar than "freq"/"weight" needs to be updated.
"freq" is still default when data is aggregated from microdata without freqVar specified (see new parameter freqVarNew).
Adaption needed after Matrix ver. 1.4-2 (not a user-visible change)