Littlewood-Richardson Calculator

The "Littlewood-Richardson Calculator" is a package of C and Maple programs for computing Littlewood-Richardson coefficients. The C programs form the engine of the package, providing fast calculation of single LR coefficients, products of Schur functions, and skew Schur functions. The Maple code mainly gives an interface which makes it possible to use the C programs from Maple. This interface uses the same notation as the SF package of John Stembridge, to make it easier to use both packages at the same time.

The Littlewood-Richardson Calculator package is open source software (under the GNU General Public License). To install it, download the file

    lrcalc-1.1.7.tar.gz
and unpack it using the (unix) commands:
    % gunzip lrcalc-1.1.7.tar.gz

    % tar xvf lrcalc-1.1.7.tar

This will create a directory named lrcalc and put all the necessary files in it. Now change to the directory and run the program ./configure to compile the programs:

    % cd lrcalc-1.1.7

    % ./configure
After that you can use the package from Maple by reading the file lrcalc. This makes the Maple commands lrcoef, tos, and skew available. Please refer to the README file in the lrcalc directory for more details, and see the CHANGELOG file for a list of bug fixes and enhancements.

UPDATE: The Littlewood-Richardson calculator has been integrated in the Sage-Combinat package for the Sage Mathematics Software System. The file lrcalc-sage-1.1.7.tar.gz has been prepared for this purpose by Nicolas M. Thiery (Nicolas.Thiery at u-psud fr) and Jean-Pierre Flori (flori at enst fr) for this purpose. This file uses the GNU automake system to compile the LR Calculator, and it may be easier to use if you have a non-standard operating system (such as if you don't use Linux.) Developers may prefer the file lrcalc-sage-hg.tar.gz which also contains Mercurial version control data.

I will be grateful for any comments or bug reports for this package. Enjoy!

Anders Skovsted Buch