# abclass 0.5.1

## Minor changes

* Replaced `qpmadr::solveqp()` with `quadprog::solve.QP()` because the {qpmadr}
  package was archived on CRAN as of 2023-01-10.


# abclass 0.5.0

## Major changes

* Simplified specification of group penalty via `abclass.control()`.

## Minor changes

* Changed the default `alignment` to `lambda` for `cv.abclass()` and `refit` in
  `et.abclass()` if a sequence of lambda's is specified.  A warning message
  would be thrown out for the former.


# abclass 0.4.0

## New features

* Added support of sparse matrix `x` of class `sparseMatrix` (provided by the
  `{Matrix}` package) for `abclass()` and `predict.abclass()`.
* Added new functions named `cv.abclass()` and `et.abclass()` for training and
  tuning the angle-based classifiers with cross-validation and an efficient
  tuning procedure for lasso-type algorithms, respectively.
  See the corresponding function documentation for details.
* Added experimental classifiers with sup-norm penalties.  See the functions
  `supclass()` and `cv.supclass()` for details.

## Major Changes

* Simplified the function `abclass()` and moved the tuning procedure by
  cross-validation to the function `cv.abclass()`.

## Minor Changes

* Changed the default values of the following arguments for
  `abclass.control()`.
  * `alpha`: from `0.5` to `1.0`
  * `epsilon`: from `1e-3` to `1e-4`

## Bug fixes

* Fixed `alignment` in `abclass.control()`.


# abclass 0.3.0

## New features

* Added experimental group-wise regularization by group SCAD and group MCP
  penalty.
* Added a new function named `abclass.control()` to specify the control
  parameters and simplify the main function interface.

## Minor changes

* Renamed the argument `max_iter` to `maxit` for `abclass()`.

## Bug fixes

* Fixed the validation indices in the cross-validation procedure


# abclass 0.2.0

## New features

* Added experimental group-wise regularization by group lasso penalty.

## Minor changes

* Removed the function call from the return of `abclass()` to avoid
  unnecessarily large returned objects
* Changed the default value of `lum_c` for `abclass()` from 0 to 1.
* Renamed the argument `rel_tol` to `epsilon` for `abclass()`.

## Bug fixes

* Fixed the first derivatives of the boosting loss
* Fixed the label prediction by using the fitted inner products instead of the
  probability estimates
* Fixed the computation of regularization terms for verbose outputs in
  `AbclassNet`
* Fixed the computation of validation accuracy in cross-validation
* Fixed the assignment of `lum_c` in the associated header files.
* Fixed the computation of lower bound for distinct observation weights


# abclass 0.1.0

## New features

* The first release of **abclass** providing the multi-category angle-based
  large-margin classifiers with various loss functions.
