README.md

Brent's univariate minimizer and zero finder

This project provides a CMake framework, that automatically downloads and builds Brent's univariate minimizer and zero finder from Netlib (https://netlib.org/c/brent.shar).

Prerequisites

What you need:

• Git (optional) for getting the code and contributing to the project
• CMake for building the project
• C compiler
  • gcc for linux/mac (https://gcc.gnu.org/)
  • cygwin + gcc for windows (https://www.cygwin.com/)

Linux (Ubuntu)

Use your distribution's package manager to install the packages cmake and gcc.

$ sudo apt-get install cmake gcc

Mac OS X

Homebrew

$ brew install cmake gcc

MacPorts

$ sudo port -v install cmake ninja clang-<XX> gcc<YY>
$ sudo port -v install gcc<YY>-libcxx +clang<XX>
$ sudo port -v install openblas +native

where you have to replace <XX> with the latest stable version of Clang and <YY> with the latest stable version of GCC (it's a dependency of OpenBLAS). You can discover all available versions of Clang and GCC like this:

$ port search --name --line --regex '^clang-?\d*\.?\d*$'
$ port search --name --line --regex '^gcc\d*$'

Windows

Install Cygwin and use the Cygwin package manager to install the packages cmake and gcc-g++.

How to compile

1. Clone the git repository or download the BrentMinimizer source code archive and unpack it to an arbitrary directory (e.g. brent-minimizer).
2. Go to the brent-minimizer directory.

   1. Type cp ./CMakeUserPresets.template.json ./CMakeUserPresets.json.

   2. Next, type cmake --workflow --list-presets. A list of available build workflows will be shown to you. It is strongly recommended to use a shared variant. You should prefer shared libraries and dynamic linking over static linking.

   3. For configuring, building and installing the project, type cmake --workflow --preset user-shared-release-install. This will try to populate the ./build directory with a CMake configuration tree, execute the build and install the project. By default, the configured installation directory is ./install.

      But it will fail due to an unaccepted license. Study the license text and proceed to the next step.

   4. Open ./CMakeUserPresets.json in your favorite editor and set "Brent_TERMS_ACCEPTED": true in the first configure preset "user-config".

   5. Repeat step 2.3. Configuring, building and installing should be successful now.

Now, the brent-minimizer code is compiled and you can use it in other projects. The installed brent-minimizer package is discoverable by CMake as BrentMinimizer. In the CMakeLists.txt of the other project, call:

find_package(BrentMinimizer CONFIG REQUIRED)

This makes the Netlib::BrentMinimizer CMake library target available to you.

Then, to help CMake discover the BrentMinimizer package, call CMake for the other project like this:

$ cmake -B ./build -DCMAKE_PREFIX_PATH=/path/to/BrentMinimizer/install/prefix

If BrentMinimizer is installed in a proper system-wide location, the CMAKE_PREFIX_PATH shouldn't be necessary.