Download - Compiling

Table of Contents

These instructions explain how to compile VLFeat on your own. This can be useful to customize or contribute to VLFeat, but it is otherwise not necessary (use the binary package instead).

Compiling on Unix

Compiling for UNIX-like platforms (e.g. Mac OS X, Linux) uses the standard GNU toolchain. 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.

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.

Mac OS X 10.6 (Snow Leopard), 64-bit, and MATLAB 2009b. MATLAB 2009b for Snow Leopard has added 64 bit mex support and a corresponding extension mexmaci64. VLFeat now supports compiling for this platform, but the architecture must be specified manually when compiling, either like:

$ make ARCH=maci64

or

$ make ARCH=maci

Unfortunately, MATLAB 2009b's mex script has a bug that must be manually fixed in order for this procedure to work correctly. It is recommend to make backup of the mex script before attempting this. Th fix the bug, edit the MATLABROOT/bin/mex script by cutting the line:

get_arch    # Call $MATLAB/bin/util/arch.sh

and pasting it after the processing of options:

...
shift
done

#PASTE get_arch call here
get_arch    # Call $MATLAB/bin/util/arch.sh

if [ $v7_compat -eq 1 ] ; then
fc_flags="$fc_flags -DMX_COMPAT_32"
...

Compiling on Windows

For Windows, the library bundles an NMake makefile (Makefile.mak). In order to use it, you must edit Makefile.mak to adjust the values of a number of configuration variables to match your setup. Once you have done that, start the Visual Studio Command Prompt and type

$ nmake /f Makefile.mak # for the Windows 32 target
$ nmake /f Makefile.mak ARCH=win64 # for the Windows 64 target

For Windows platform, it is also possible to compile just the MATLAB MEX files from within MATLAB (using the vl_compile command). This is meant to help less experienced users that may need to recompile the mex file due to binary incompatibilities with older MATLAB versions.

Windows troubleshooting

syntax error: '=' unexpected:

Use nmake /f Makefile.mak. Without /f, nmake will default to the wrong makefile.

'long' followed by 'long' is illegal:

This error is usually caused by attempting to compile outside of the Visual Studio Command Prompt.