A. Requirements

Torch compilation requires a number of standard packages described below:

Concerning the compiler, if you do not have already Visual Studio, then install the freely available Microsoft Visual Studio 2008 (Express Edition). You need the C++ compiler.

Download the CMake Win32 installer and install CMake.

Install Tortoise SVN.

If you want graphics, you should install QT 4.4. Torch will compile if you do not, but you will not be able to produce plots or handle widgets. Trolltech produces QT binaries for Windows, but unfortunately they are not compiled with the Microsoft Visual Studio compiler. You will have to follow simple instructions to compile and install it.

B. Getting Torch sources

You can download the last tarball sources and unpack it using for e.g. Winzip.

However, we recommend to use the subversion repository to keep bleeding edge sources. Start TortoiseSVN for that purpose: right-click in the explorer at the place you want to checkout Torch repository. Choose TortoiseSVN -> Export .... Then enter as URL

Choose the directory you want for Torch sources, and click Ok.

C. Configuring Torch

We use CMake for configuring Torch. Start CMake application. Set the source path to the directory where you downloaded Torch. Set as a build path another directory you like. This eases cleaning up built objects, but also allow you to build Torch with various configurations (e.g. Release and Debug in two different build directories).

Click Configure, choose Visual Studio 9 2008 if you downloaded the last version of Visual Studio (if not, select the compiler version you have).

Make sure you chose the Release and not Debug version (well, except if you want the Debug version!) to compile (Variable CMAKE_BUILD_TYPE). Also, if you do not have the administrator rights, you might not be able to install Torch in the directory set in variable CMAKE_INSTALL_PREFIX which is by default C:/Program Files/Torch. Change the variable to the install path you would like.

Click Configure until Generate is clickable. Click Generate.

Please, see CMake documentation or at least some of our CMake hints for more details on configuration.

D. Compiling and installing

If CMake configuration went fine, a Visual Studio project should have been generated in your build directory. Double-click the project. Build the solution. If everything went fine, you can then install it by building the target INSTALL.

D. Running Torch

Now Torch should be installed. If you did not changed CMAKE_INSTALL_PREFIX, it should be in C:/Program Files/Torch. Lua executables (lua and qlua) are found in the bin sub-directory of these installation directories. Start lua by double-clicking it, and try it out!

Lua 5.1.3  Copyright (C) 1994-2008 Lua.org, PUC-Rio
> require 'torch'
> = torch.Tensor(5):zero()

[torch.Tensor of dimension 5]

The executable lua is a simple Lua interpreter (as provided on Lua website), while qlua has enhanced interactivity (like completion) and is able to handle graphics and QT widgets.