NLopt Installation
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 and/or Matlab installed if you want to install the Octave and/or Matlab plugins, respectively.
In particular, NLopt uses the standard CMake cmake
build system, which means that you compile it via:
mkdir build
cd build
cmake ..
make
in the nlopt
directory. Then install the NLopt libraries and header files via:
sudo make install
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.
In the following, we describe a few details of this installation process, including how to change the installation location.
Changing the installation directory
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.
For example, suppose that you want to install into the install
subdirectory of your home directory ($HOME
). You would do:
cmake -DCMAKE_INSTALL_PREFIX=$HOME/install ..
make
make install
This will create the directories $HOME/install/lib
etcetera and install NLopt into them. However, now when you compile code using NLopt, you will need to tell the compiler where to find the NLopt header files (using -I
) and libraries (using -L
) with something like:
cc -I$HOME/install/include myprogram.c -L$HOME/install/lib -lnlopt -lm -o myprogram
See also below for how to change the installation directories for Octave, Matlab, and Guile plugins, if you are installing those.
Note also that the -DCMAKE_INSTALL_PREFIX
flag will change the location where the Python plugins are installed, so you may need to change the Python module search path via the PYTHONPATH
environment variable.
However, at this point you need to tell the operating system where to find the shared library, so that the runtime linker works properly. There are at least two ways to do this. First, you can use the LD_LIBRARY_PATH
environment variable. For example, if you installed into the /foo/bar
directory, so that the library is in /foo/bar/lib
, then you would do
export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:/foo/bar/lib
in the bash shell, or
setenv LD_LIBRARY_PATH ${LD_LIBRARY_PATH}:/foo/bar/lib
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
.
Static libraries
By default, NLopt compiles as a shared library (also called a dynamic-link library). The alternative is to compile NLopt as a static library.
Compiling NLopt as a static library is easy. Just add -DBUILD_SHARED_LIBS=OFF
to the cmake
flags, as in:
cmake -DBUILD_SHARED_LIBS=OFF ..
Then you run make
and make
install
as usual.
Octave and Matlab plugins
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).
Matlab
In particular, for Matlab plugins to be installed, you should provide the Matlab installation dir, eg:
cmake -DMatlab_ROOT_DIR=/opt/matlab/RYYYYx/ ..
Some versions of Matlab also require that you compile NLopt as a shared library in order to produce a Matlab plugin; see below.
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):
cmake -DINSTALL_MEX_DIR=dir ..
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).
Matlab's standard C++ library might be incompatible with the one used by your compiler, in that case you can try to disable the C++ algorithms:
cmake -DNLOPT_CXX=OFF ..
Octave
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.
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 to 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:
cmake -DINSTALL_OCT_DIR=octdir -DINSTALL_M_DIR=mdir ..
Python plugins
If Python 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 to be installed, as NLopt's Python interface uses NumPy array types.
To specify a particular version or location of Python, use the Python_EXECUTABLE
variable to set the full path to the python
executable:
cmake -DPython_EXECUTABLE=/usr/bin/python ..
GNU Guile plugins
If 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.
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.
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:
cmake -DGUILE_EXECUTABLE=/usr/bin/guile GUILE_CONFIG_EXECUTABLE=/usr/bin/guile-config ..
(The cmake
script uses these programs to determine the compiler flags and installation directories for Guile plugins.)
By default, the Guile plugin is installed in the guile extension directory defined relatively to the installation prefix.
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 by changing the %load-path
variable in Guile or using the GUILE_LOAD_PATH
environment variable.
NLopt with C++ algorithms
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 subroutines written in C (or written in Fortran and converted to C) and C++. If you configure with:
cmake -DNLOPT_CXX=OFF ..
however, it will disable algorithms implemented in C++ (StoGO and AGS algorithms).
The resulting library has the same interface as the ordinary NLopt library, and can still be called from ordinary C, C++, and Fortran programs. However, one no longer has to link with the C++ standard libraries, which can sometimes be convenient for non-C++ programs, and allows libnlopt to be compatible with multiple C++ compilers simultaneously.