# nloptr 2.1.1

This is a patch release to work around a bug in the CRAN checks. Specifically,
one of the unit tests for the `isres()` algorithm was failing on some CRAN
builds because convergence is stochastic with slightly different results even
with the same fixed seed prior to calling the function.

# nloptr 2.1.0
This release deprecates the default behavior of the inequality equations in any
wrapper function which uses them. Currently, they are calibrated to be >= 0.
This version allows for the equations to be consistent with the main `nloptr`
function, which requires <= 0. In a future release, the default behavior will
switch to assuming the calibration is <= 0, and eventually, the >= 0 behavior
will be removed. It also includes a large number of safety and efficiency
changes, and an expansion of the unit tests to 100% coverage for all files but
one. The major changes include:

* Reversed the direction of the inequality equations `hin` and `hinjac` in the
wrapper functions which use them, bringing them into compliance with the main
`nloptr` call. This addresses
[Issue #148](https://github.com/astamm/nloptr/issues/148);
* Cleaned the Hock-Schittkowski problem no. 100, Hartmann 6-dimensional, and
Powell exponential examples. This addresses
[Issue #152](https://github.com/astamm/nloptr/issues/152) and
[Issue #156](https://github.com/astamm/nloptr/issues/156);
* Updated roxygen version;
* Updated maintainer email;
* Deal with NA returns from `parallel::detectCores()` (contributed by @jeroen in 
PR #150);
* Setup rhub v2 checks;
* Update cmake installation instructions on Mac with brew (#146);
* Allow use of equality constraints with COBYLA (#135);
* Replaced the unit testing framework of `testthat` with `tinytest` (See 
[Issue #136](https://github.com/astamm/nloptr/issues/136));
* Brought coverage of `is.nloptr` to 100%. The only file not completely covered
by unit tests is `nloptr.c`. The uncovered calls are error messages which get
trapped by tests in R before the call gets to C;
* Linted package for code correctness and consistency;
* Updated vignette, DESCRIPTION, and NEWS;
* Updated package website to use bootstrap 5;
* Expanded unit tests: coverage now over 97% with no file below 90%;
* Removed forcing `C++11`;
* Added safety checks to C code;
* Added many safety and efficiency enhancements to R code;
* Most R code style made self-consistent;
* Updated documentation and messages for accuracy and mathematical formatting
* Updated Github actions;
* Some bugfixes (e.g. in `isres` or the warning in `nl.grad`).

Please see the commit logs for more detailed descriptions of the changes.

# nloptr 2.0.3

* Improved compatibility on RHEL/CentOS by first searching for a `cmake3` binary
  on the `PATH` ([#104](https://github.com/astamm/nloptr/issues/104)).
* Improved backward compatibility with older versions of `cmake`
  ([#119](https://github.com/astamm/nloptr/issues/119)).

# nloptr 2.0.2

This is a patch version in which:

* I link to the `nlopt` library via `nlopt/lib/libnlopt.a` instead of
`-Lnlopt/lib -lnlopt` when building `nlopt` from included sources to avoid
potential mess where `-lnlopt` could look for the `nlopt` library in other
places and possibly link with an existing too old system build of `nlopt`.

Additionally, we contacted [Simon Urbanek](https://github.com/s-u/) for updating
the `nlopt` recipe for macOS users so that it does now match the latest
`v2.7.1`, which should avoid `nlopt` to be built on the fly on CRAN machines.

# nloptr 2.0.1

This is a release mainly for increasing direct compatibility with most user
cases. In details, here is the list of changes that have been made:

* Update `SystemRequirements` description to make it clearer which minimal
  versions of `cmake` (`>= 3.15.0`) and `nlopt` (`>= 2.7.0`) are required
  ([#100](https://github.com/astamm/nloptr/issues/100),
  [@HenrikBengtsson](https://github.com/HenrikBengtsson)).
* End configuration sooner and louder if `cmake` is missing when needed with
  clearer message ([#103](https://github.com/astamm/nloptr/issues/103),
  [@eddelbuettel](https://github.com/eddelbuettel)).
* Ensure system-wide installation of `cmake` in the list of suggestions to
  install it when missing.
* Update GHA scripts to latest versions.
* Configure git to always use LF line endings for configure.ac file.
* Add CI for R-devel on Windows with Rtools42.
* Fix for compatibility with versions of R anterior to `4.0`
  ([#111](https://github.com/astamm/nloptr/issues/111)).
* Look for a `cmake3` binary in the current path before `cmake` for increasing
  compatibility with most RHEL/CentOS users
  ([#104](https://github.com/astamm/nloptr/issues/104),
  [@bhogan-mitre](https://github.com/bhogan-mitre),
  [@HenrikBengtsson](https://github.com/HenrikBengtsson)).

# nloptr 2.0.0

## Major changes

* Use [CMake](https://cmake.org) to build `nlopt` from included sources on macOS
  and on Linux if no system build of NLopt (>= 2.7.0) is found.
* Update included sources of NLopt to latest version (2.7.1).
* Put back the ability on Linux platforms to re-use an existing external build
  of NLopt instead of building from the included sources (contributed by
  [Dirk Eddelbuettel](https://github.com/eddelbuettel),
  [#88](https://github.com/astamm/nloptr/issues/88)).
* Now builds using NLopt from `rwinlib` on Windows current release (contributed
  by [Jeroen Ooms](https://github.com/jeroen),
  [#92](https://github.com/astamm/nloptr/issues/92)), or NLopt from `Rtools42`
  on Windows devel (contributed by
  [Tomas Kalibera](https://github.com/kalibera)).

## Minor changes

* Added a `NEWS.md` file to track changes to the package.
* Use markdown in Roxygen documentation.
* Added a logo and a proper
  [**nloptr** website](https://astamm.github.io/nloptr/).
* Added coverage.
* Switch from Travis to Github Actions for CI.
* Use Catch for unit testing C/C++ code.
* Now tracking code coverage.
* Update NLopt-related URLs following migration of
  [NLopt website](https://nlopt.readthedocs.io/en/latest/).
* Fixed bug to avoid linking issues when using the C API via
  `#include <nloptrAPI.h>` in several source files.
* Fix precision issue in test example `hs071`
  ([#81](https://github.com/astamm/nloptr/issues/81), 
  [@Tom-python0121](https://github.com/Tom-python0121)).
* Made NLopt algorithm `NLOPT_GN_ESCH` available from R interface
  (contributed by [Xiongtao Dai](https://github.com/xdaiISU)).

# nloptr 1.2.2 (29 February 2020)
* Replaced deprecated functions from [**testthat**](https://testthat.r-lib.org)
  framework in unit tests (contributed by
  [Avraham Adler](https://github.com/aadler)).

## 26 February 2020:
* Fixed warnings (as requested by CRAN): R CMD config variables 'CPP' and
  'CXXCPP' are deprecated.

## 20 October 2018:
* Exposed CCSAQ algorithm in R interface (contributed by
  [Julien Chiquet](https://github.com/jchiquet)).

# nloptr 1.2.1 (03 October 2018)
* Build process was changed to solve issues on several OS (many thanks to the
  CRAN maintainers).

# nloptr 1.2.0 (30 September 2018)

## 21 April 2018:
* Changed installation procedure. NLopt source code is now part of nloptr
  package and not downloaded separately during configure in Unix systems in case
  NLopt library cannot be found.
* Registered NLopt C functions to be used by external R package and included C
  API.
* Documentation is generated using roxygen.

## 25 September 2017:
* Fixed a bug in auglag. BOBYQA is now allowed as local solver
  (thanks to [Léo Belzile](https://github.com/lbelzile)).

# nloptr 1.1.0 (22 August 2016)
* Fixed a bug that sometimes caused segmentation faults due to an uninitialized
  vector of tolerances for the inequality and/or equality constraints
  (thanks to Florian Schwendinger).

# nloptr 1.0.9 (22 March 2015)
* When the problem fails with error status 6 (`NLOPT_MAXTIME_REACHED`) and
  `maxtime` was not set to a positive number in the options, then nloptr tries a
  couple more times to solve the problem. This is a new approach that should
  solve the bug that NLopt sometimes exits a problem stating the maximum
  available time has been reached, even when no limit on the time has been set.
* Changed warning to message in order to show that for consistency with the rest
  of the package the inequality sign in the functions `auglag`, `cobyla`,
  `isres`, `mma`, and `slsqp` will be switched from >= to <= in a future nloptr
  version.

# nloptr 1.0.8 (22 February 2015)
* Changed description in DESCRIPTION such that it does not start with the
  package name (as requested by CRAN).

# nloptr 1.0.7 (14 February 2015)
* Changed title field in DESCRIPTION to title case (as requested by CRAN).
* Added `donttest` around example in `mma` documentation.

# nloptr 1.0.6 (8 February 2015)
* Updated description to better reflect installation procedure on Linux when
  NLopt is pre-installed (as requested by CRAN).

# nloptr 1.0.5 (28 January 2015)
* Added non-exported functions CFlags and LdFlags to be used in packages that
  want to link to the NLopt C library.
* For consistency with the rest of the package the inequality sign in the
  functions `auglag`, `cobyla`, `isres`, `mma`, and `slsqp` will be switched
  from >= to <= in the next nloptr version. The current version of nloptr shows
  a warning when using these functions with inequality constraints. This warning
  can be turned off with `options('nloptr.show.inequality.warning' = FALSE)`.

# nloptr 1.0.4 (02 August 2014)
* Increased version number to re-submit package to CRAN with CRLF line endings
  removed from `configure` and `configure.ac`.

# nloptr 1.0.3 (25 July 2014)
* Changed NLOPT_VERSION to 2.4.2 for Linux.
* Changed `nloptr.default.options` from a `data.frame` to a function returning
  the `data.frame`.

# nloptr 1.0.2 (25 July 2014)
* Added configure script which tests for a system NLopt library via pkg-config
  and uses it if it is sufficiently recent (ie 2.4.*), and otherwise configure
  downloads, patches and builds the NLopt sources just how src/Makevars used to
  (thanks to  [Dirk Eddelbuettel](https://github.com/eddelbuettel)).

# nloptr 1.0.1 (05 May 2014)
* All unit tests are now enabled and use the package testthat. Install the
  package with argument INSTALL_opt = "--install-tests" supplied to
  `install.packages` to install the tests. The tests can be run after
  installation with test_package('nloptr'). The testthat package needs to be
  installed and loaded to be able to run the tests.
* Changed default value for maxtime option from 0.0 to -1.0. In some cases
  nloptr returned `NLOPT_MAXTIME_REACHED` without running any iterations with
  the default setting. This change solves this.
* Replaced cat by message or warning. Messages can be suppressed by
  `suppressMessages`.

# nloptr 1.0.0 (27 January 2014)
* Merged wrappers from the **nloptwrap** package.

# nloptr 0.9.6 (19 November 2013)
* Added a line in `Makevars` to replace some code in NLopt to fix compilation on
  Solaris as requested by Brian Ripley.

# nloptr 0.9.5 (12 November 2013)
* Updated references from NLopt version 2.3 to NLopt version 2.4 in installation
  instructions in `INSTALL.windows`.
* Added a line in `Makevars` that replaces some code related to type-casting in
  `NLopt-2.4/isres/isres.c`.
* Changed encoding of `src/nloptr.c` from CP1252 to UTF-8.

# nloptr 0.9.4 (09 November 2013)
* Updated NLopt to version 2.4.
* Changed tests to use unit testing package testthat (these are currently
  disabled).
* Fixed a segfault that started to occur on the latest version of Ubuntu.
* Slightly changed the build process (Removed `-lstdc++` from linker statement.
  A file `dummy.cpp` (with C++ extension) is added to the source directory to
  ensure linking with C++. Thanks to Brian Ripley for bringing this up.)

# nloptr 0.9.3 (31 July 2013)
* Split lines longer than 100 characters in `check.derivatives` examples in two
  lines to comply with new package rules.
* Moved vignettes from `inst/doc` to `vignettes` to comply with new package
  rules.
* Removed dependency on `apacite` in vignette as an update of `apacite` on CRAN
  resulted in errors.

# nloptr 0.9.2 (11 July 2013)
* Made changes in bibtex file of documentation.
* Removed `CFLAGS`, `CXXFLAGS` from `Makevars`.

# nloptr 0.9.0
* Introduced new `print_level = 3`. Shows values of controls
  (16 April 2012 on R-Forge).
* Changed `Makevars` and `Makevars.win` to link to version 2.3 of NLopt compiled
  with `--with-cxx` option. This makes the StoGo algorithm available.
  (31 April 2013 on R-Forge).

# nloptr 0.8.9 (18 November 2011)
* Changed CRLF and CR line endings in `src/Makevars` to LF line endings to
  remove a warning from R CMD check.
* Adopted some changes proposed by Brian Ripley to `src/Makevars.win` in order
  for nloptr to work with his new toolchain.

# nloptr 0.8.8 (28 September 2011)
* Updated `src/Makevars` to compile on Solaris.

# nloptr 0.8.7 (24 September 2011)
* Updated `src/Makevars` to compile on Solaris.

# nloptr 0.8.6 (19 September 2011)
* Updated `src/Makevars` to compile on Solaris.

# nloptr 0.8.5 (03 September 2011)
* Updated `src/Makevars` to compile a working binary for MacOS.

# nloptr 0.8.4 (12 August 2011)
* added new options:
	- data/nloptr.default.options.R: new file with a description of all options,
	  mostly taken from the NLopt website (for internal use).
	- R/nloptr.print.options.R: function to show the description for a specific
	  (set of) option(s). E.g. `nloptr.print.options(option="maxeval")`.
	  `nloptr.print.options()` shows a description of all options if called
	  without arguments.
	- added option to print a description of all options and their values
	  (`print_options_doc` = TRUE/FALSE).
	- added option population to set the population of stochastic/global solvers
	  (`population` = 1000).
	- added option ranseed which sets the random seed for stochastic solvers
	  (`ranseed` = 3141). A value of 0 uses a random seed generated by system time.
	- option check_derivatives is no longer listed as a termination condition.
	- documented the option to set the tolerance of (in)equality constraints
	  (`tol_constraints_eq`, `tol_constraints_ineq`).

* `tests/banana_global.R`: new test file that uses the algorithms
  (CRS, ISRES, MLSL) and options `ranseed` and `population`.
* `src/nloptr.c`: capture error codes from setting options.
* `R/nloptr.print.R`: output gives 'optimal value of controls' when status = -4
  (some error code), this is changed to 'current value of controls'.
