Every convex polyhedron P has two representations, one as the intersection of finite halfspaces and the other as Minkowski sum of the convex hull of finite points and the nonnegative hull of finite directions. These are called H-representation and V-representation, respectively.
CddInterface is a gap interface with the C package Cddlib which among other things can translate between H,V- representations of a polyhedron P and solve linear programming problems over P, i.e. a problem of maximizing and minimizing a linear function over P. A list of all available operations can be found in the manual.pdf.
To use CddInterace, it has to be compiled. That means you need at the very least a C compiler on your system. If you managed to install GAP, you probably already have one, so we won't cover this here. However, various other prerequisites are needed, described below.
If you are building CddInterface directly from git, you first need
to generate the configure script. This require autoconf. On
Debian and Ubuntu, you can install it via
sudo apt-get install autoconf
On macOS, if you are using Homebrew, you can install it via
brew install autoconf
Then run
./autogen.sh
Now proceed as in the next section
Compiling CddInterface requires development headers for the GMP library as well as for cddlib. On Debian or Ubuntu, you can install these via
sudo apt-get install libgmp-dev libcdd-dev
On macOS, if you are using Homebrew, you can install them via
brew install gmp cddlib
Most other package managers include comparable packages, at least for GMP. For cddlib, if your package manager does not provide it, we describe further down how to install it yourself.
Assuming the prerequisites are present (see the previous section), you can now build cddlib as follows:
./configure --with-gaproot=path/to/gaproot
make
where the path/to/gaproot is the path to the folder where you installed and
compiled GAP and which contains the file sysinfo.gap. The default value is
../...
For a simplified installation, try the following command in the main CddInterface directory
./install.sh path/to/gaproot
If that does not work, try the following:
Go inside the CddInterface directory and download some release of cddlib and extract it. For example the release 0.94m:
wget https://github.com/cddlib/cddlib/releases/download/0.94m/cddlib-0.94m.tar.gz
tar xvf cddlib-0.94m.tar.gz
ln -sf $(pwd)/cddlib-0.94m $(pwd)/current_cddlib
After that, compile cddlib via
cd current_cddlib
mkdir build
./bootstrap
./configure --prefix=$(pwd)/build
make
make install
Cdd should now be installed in the build directory. After that, go back to the CddInterface main folder
and install CddInterface with the following commands
./autogen.sh
./configure --with-gaproot=path/to/gaproot --with-cddlib=$(pwd)/current_cddlib/build
make
After that, you should be able to load CddInterface.
To create the documentation:
gap makedoc.g
To run the test files
gap tst/testall.g
The package can be updated using the following commands
git pull
make
With docker app you can run an image of the newest version of gap && CddInterface via the command
docker run -it kamalsaleh/gap_packages
If you want to experiment online with the package you can use notebook.ipynb vie the binder link below.
Of course you are welcome to e-mail me if there are any questions, remarks, suggestions ;)
Kamal Saleh e-mail: saleh@mathematik.uni-siegen.de
CddInterface is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.