
First of all you should choose a group by clicking on the button "group".
The different details for the group selection are
described at this page. Together with the desired automorphism
group you automatically prescribe the point set of the design: it is fixed as
V = {1, ..., v} where v is the degree of the group.

As soon as you have prescribed an automorphism group, you have to specify the
other parameters of the design: blocksize k, t and lambda. Click here for more information on the choice and the
restrictions for the parameters.

Now you can start the calculation of the KramerMesner matrix
. This matrix M shows the incidence relations between the orbits of the
prescribed group on the tsubsets (rows) and the orbits on the ksubsets of
V (columns).
 Finding designs with the given parameter set is then equivalent to solving the equation M · v = (lambda, ..., lambda)^{T} with the KramerMesner matrix M. So the next thing to do is to start one of the given solvers for this system of diophantine equations.
Anton Betten,
Evi Haberberger,
Reinhard
Laue,
Alfred
Wassermann:
The program DISCRETA
Here we want to give you a short survey on how you can work with DISCRETA and construct designs (for the description of the KramerMesner method we use, click here ).
After the start of the program you get the main DISCRETA window:
Back to the DISCRETAhomepage.
Last updated: August 24, 1999, Evi Haberberger