Changes in version 0.3.2 (2024-09-22)                  

    o   Do not use sourceCpp in tests where the files include
	[[Rcpp::plugins(openmp)]] when OpenMP is not supported.

                 Changes in version 0.3.1 (2022-03-02)                  

    o   the BFGS implementation supports an aboslute convergence treshold.

    o   the user can provide pre-allocated memory to the C++ API for the BFGS
	implementation.

                 Changes in version 0.3.0 (2021-12-12)                  

    o   it is possible to mask (fix) some of the parameters. Non-linear equality
	constraints are also supported with an augmented Lagrangian method.

    o   the code has been refactored. This may yield a speedup in some cases.

    o   computation of the hessian is now supported using numerical differentiation
	with Richardson extrapolation to refine the estimate.

    o   the gradient norm can be used as a convergence criterion.

    o   a diagonal preconditioning method has been added to the psqn method. This
	requires that one defines PSQN_W_LAPACK prior to including the header files
	from the package and links with LAPACK and BLAS.

    o   the license has been changed to the Apache license.

                 Changes in version 0.2.1 (2021-05-04)                  

    o   tests that compile files using Rcpp::sourceCpp() now do so in a temporary
	directory in tempdir(). It was done before in the package directory which
	violates CRAN policies.

                 Changes in version 0.2.0 (2021-04-17)                  

    o   added a generic method for partially separable functions.

    o   made it possible to run a setup function prior to evaluating all the element
	functions. Thus, some computations may be done once if possible. See
	https://github.com/boennecd/psqn-va-ex for an example.

    o   made it possible to change the unsigned integer type used in the package by
	defining the PSQN_SIZE_T macro prior to including the header files from the
	package.

    o   added the incomplete Cholesky factorization preconditioner from Eigen to the
	package. This requires that one defines the PSQN_USE_EIGEN macro prior to
	including the header files from the package.

                 Changes in version 0.1.0 (2020-10-27)                  

    o   first submission to CRAN.

    o   bug fixes of bugs found on CRAN's checks.

    o   minor improvements.