5 The installation of NLopt is fairly standard and straightforward, at least on Unix-like systems (GNU/Linux is fine). It doesn't require any particular packages to be installed except for a C compiler, although you need to have [Octave](https://en.wikipedia.org/wiki/GNU_Octave) and/or Matlab installed if you want to install the Octave and/or Matlab plugins, respectively.
7 In particular, NLopt uses the standard [CMake](https://cmake.org/) `cmake` build system, which means that you compile it via:
16 in the `nlopt` directory. Then install the NLopt libraries and header files via:
22 By default, this installs the NLopt shared library (`libnlopt.so`) in `/usr/local/lib` and the NLopt header file (`nlopt.h`) in `/usr/local/include`, as well manual pages and a few other files.
24 In the following, we describe a few details of this installation process, including how to change the installation location.
26 Changing the installation directory
27 -----------------------------------
29 You may wish to install NLopt in a directory other than `/usr/local`, especially if you do not have administrator access to your machine. You can do this using the `CMAKE_INSTALL_PREFIX` variable of the `cmake` utility.
31 For example, suppose that you want to install into the `install` subdirectory of your home directory (`$HOME`). You would do:
34 cmake -DCMAKE_INSTALL_PREFIX=$HOME/install ..
39 This will create the directories `$HOME/install/lib` etcetera and install NLopt into them. However, now when you compile code using NLopt, you will need to tell the compiler where to find the NLopt header files (using `-I`) and libraries (using `-L`) with something like:
42 cc -I$HOME/install/include myprogram.c -L$HOME/install/lib -lnlopt -lm -o myprogram
45 See also below for how to change the installation directories for Octave, Matlab, and Guile plugins, if you are installing those.
47 Note also that the `-DCMAKE_INSTALL_PREFIX` flag will change the location where the Python plugins are installed, so you may need to change the [Python module search path](http://docs.python.org/tutorial/modules.html#the-module-search-path) via the `PYTHONPATH` environment variable.
49 However, at this point you need to tell the operating system where to find the shared library, so that the runtime linker works properly. There are at least two ways to do this. First, you can use the `LD_LIBRARY_PATH` environment variable. For example, if you installed into the `/foo/bar` directory, so that the library is in `/foo/bar/lib`, then you would do
52 export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:/foo/bar/lib
55 in the [bash](https://en.wikipedia.org/wiki/Bash) shell, or
58 setenv LD_LIBRARY_PATH ${LD_LIBRARY_PATH}:/foo/bar/lib
61 in [csh](https://en.wikipedia.org/wiki/csh) or [w:tcsh](https://en.wikipedia.org/wiki/tcsh).
63 Alternatively, in GNU/Linux systems, you can add the library directory to the system-wide file `/etc/ld.so.conf` and then (as root) run `/sbin/ldconfig`. [Category:NLopt](index.md)
68 By default, NLopt compiles as a shared library (also called a dynamic-link library). The alternative is to compile NLopt as a static library.
70 Compiling NLopt as a static library is easy. Just add `-DBUILD_SHARED_LIBS=OFF` to the `cmake` flags, as in:
73 cmake -DBUILD_SHARED_LIBS=OFF ..
76 Then you run `make` and `make` `install` as usual.
79 Octave and Matlab plugins
80 -------------------------
82 When you compile NLopt using the above commands, it will automatically compile plugins for both Matlab and GNU Octave (a free Matlab clone) if the latter programs are installed. On most current systems, Matlab and Octave plugins require NLopt to be compiled as a shared library (see above).
86 In particular, for Matlab plugins to be installed, you should provide the Matlab installation dir, eg:
89 cmake -DMatlab_ROOT_DIR=/opt/matlab/RYYYYx/ ..
92 Some versions of Matlab also require that you compile NLopt as a shared library in order to produce a Matlab plugin; see below.
94 The Matlab plugins (along with help files and other `.m` files) are installed into `INSTALL_MEX_DIR`. You can override the default by passing a `INSTALL_MEX_DIR` to `cmake`, via (in addition to other `cmake` arguments):
97 cmake -DINSTALL_MEX_DIR=dir ..
100 to install the Matlab plugins in directory *dir*. In this case, however, when you run Matlab you will either need to run in the *dir* directory or explicitly add *dir* to your Matlab path (see the Matlab `path` command).
104 For the Octave plugins to be installed, you need to have the Octave `mkoctfile` program in your PATH. `mkoctfile` is Octave's equivalent of `mex`. If you are using a GNU/Linux system, and you installed Octave using one of the precompiled packages for your distribution, then you probably need to install a *separate package* to get `mkoctfile`. For example, on Debian you need to install the `octave-headers` package, and on Redhat you need the `octave-devel` package.
106 By default, the compiled Octave plugins (`.oct` files) are installed into the octave extension binary directory relatively to the installation prefix (usually something like `/usr/local/lib/octave/2.1.73/site/oct/i486-pc-linux-gnu`), and the .m script files are installed into the site extension directory relatively the the installation prefix (usually something like `/usr/local/share/octave/2.1.73/site/m/`). You can change these defaults by passing `INSTALL_OCT_DIR` and `INSTALL_M_DIR`, respectively, to the cmake script, via:
109 cmake -DINSTALL_OCT_DIR=octdir -DINSTALL_M_DIR=mdir ..
115 If [Python](https://en.wikipedia.org/wiki/Python_(programming_language)) is installed on your machine, and you configured NLopt as a shared library (see above), then NLopt will automatically compile and install a Python `nlopt` module. You also need [NumPy](https://en.wikipedia.org/wiki/NumPy) to be installed, as NLopt's Python interface uses NumPy array types.
117 To specify a particular version or location of Python, use the `PYTHON_EXECUTABLE` variable to set the name of the `python` executable:
120 cmake -DPYTHON_EXECUTABLE=python ..
126 If [Guile](https://en.wikipedia.org/wiki/GNU_Guile) is installed on your machine, and you configured NLopt as a shared library (see above), then a Guile `nlopt` module will automatically be compiled and installed.
128 Note that many GNU/Linux distributions come with only the Guile program and shared libraries pre-installed; to compile the NLopt plugin you will also need the Guile programming header files, which are usually in a `guile-dev` or `guile-devel` package that you must install separately.
130 If you want to specify a particular version or a nonstandard location of Guile, you should use the `GUILE_CONFIG_EXECUTABLE` and `GUILE_EXECUTABLE` variables to specify the locations of the `guile-config` and `guile` programs:
133 cmake -DGUILE_EXECUTABLE=guile GUILE_CONFIG_EXECUTABLE=guile-config ..
136 (The `cmake` script uses these programs to determine the compiler flags and installation directories for Guile plugins.)
138 By default, the Guile plugin is installed in the guile extension directory defined relatively to the installation prefix.
140 Note, however, that if you do this then Guile may not know where to load the `nlopt` module from. You can [update the Guile load path](http://www.gnu.org/software/guile/manual/html_node/Build-Config.html) by changing the `%load-path` variable in Guile or using the `GUILE_LOAD_PATH` environment variable.
142 NLopt with C++ algorithms
143 -------------------------
145 NLopt, as-is, is callable from C, C++, and Fortran, with optional Matlab and GNU Octave plugins (and even installs an `nlopt.hpp` C++ header file to allow you to call it in a more C++ style). By default, it includes only subroutines written in C (or written in Fortran and converted to C), to simplify linking. If you configure with:
148 cmake -DNLOPT_CXX=ON ..
151 however, it will also include algorithms implemented in C++ (currently, just the StoGO algorithm), and the resulting library will be called `libnlopt_cxx` and is linked with `-lnlopt_cxx`.
153 The `libnlopt_cxx` has the *same* interface as the ordinary NLopt library, and can *still* be called from ordinary C and Fortran programs. However, to use it you must also *link* with the C++ standard libraries. The easiest way to do this is to link with the C++ linker: compile your source files into `.o` object files, and then call the C++ compiler to link these `.o` files with `-lnlopt_cxx` into your executable program.
155 It is because this linking process is somewhat annoying, and it only adds a single more algorithm (StoGO) to NLopt, that by default we omit StoGO to create a library that does not require the C++ standard libraries to link.