Changes in version 0.3.1 * the BFGS implementation supports an aboslute convergence treshold. * the user can provide pre-allocated memory to the C++ API for the BFGS implementation. Changes in version 0.3.0 * it is possible to mask (fix) some of the parameters. Non-linear equality constraints are also supported with an augmented Lagrangian method. * the code has been refactored. This may yield a speedup in some cases. * computation of the hessian is now supported using numerical differentiation with Richardson extrapolation to refine the estimate. * the gradient norm can be used as a convergence criterion. * 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. * the license has been changed to the Apache license. Changes in version 0.2.1 * 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 * added a generic method for partially separable functions. * 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. * 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. * 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 to 0.1.4 * first submission to CRAN. * bug fixes of bugs found on CRAN's checks. * minor improvements.