General instructions

Compiling for UNIX-like platforms (e.g. GNU/Linux, Mac OS X) assumes that the standard GNU toolchain is available. In particular, while compilers other than GCC can be used, the compilation scripts require GNU/make.

To compile the library, it is usually sufficient to change to VLFeat root directory, denoted VLFEATROOT in the following, and type make:

$ cd VLFEATROOT
$ make

The make script attempts to automatically detect the host architecture and configure itself accordingly. If the architecture is not detected correctly, it can be specified manually. For instance

$ make ARCH=glnx86

compiles for GNU/Linux 32-bit. make help can be used to obtain a list of other useful options. You can also use make info to obtain a list of the configuration parameters used by the Makefile, which might allow you do debug any potential issue.

Compiling MATLAB support

In order for MATLAB support to be compiled, the MATLAB mex script must be in the current path. If it is not, its location must be passed to make as follows. First, determine MATLAB's root directory by running a MATLAB session and issuing the matlabroot command. Let MATLABROOT denote the returned path (e.g. /Applications/MATLAB_R2009b.app/). The mex script is usually located in MALTABROOT/bin/mex. Then run the compilation with the command

$ make MEX=MATLABROOT/bin/mex

VLFeat must be compiled for the architecture used by MATLAB (run MATLAB's computer command to obtain this information). On Mac OS X it is often necessary to turn on 64-bit support explicitly by setting ARCH=maci64 as both the 32 and 64 bit versions are plausible targets on 64-bit machines.

Compiling Octave support

Octave support is still experimental. Similarly to MATLAB, Octave requires compiling MEX files. This can be turned on by passing to make the path to the mkoctfile command:

$ make MKOCTFILE=/path/to/mkoctfile

Mac OS X troubleshooting

Since macOS CLang compiler does not support OpenMP, this is disabled by default on this platform. To use it, install Brew llvm:

$ brew install llvm

Then, use the Brew CLang compiler to compile VLFeat, as follows::

$ make CC=BREWROOT/opt/llvm/bin/clang DISABLE_OPENMP=no

Here BREWROOT is the path to Brew installation.