The Deviation Constraint

This paper introduces DEVIATION, a soft global constraint to obtain balanced solutions. A violation measure of the perfect balance can be defined as the Lp norm of the vector variables minus their mean. SPREAD constraints the sum of square deviations to the mean [5, 7] i.e. the L2 norm. The L1 norm is considered here. Neither criterion subsumes the other but the design of a propagator for L1 is simpler. We also show that a propagator for DEVIATION runs in O(n) (with respect to the number of variables) against O(n2 ) for SPREAD.

• Type: Conference
• Year: 2007
• Where: CPAIOR
• Authors: Pierre Schaus, Yves Deville, Pierre Dupont, Jean-Charles Régin
• Keywords: CPAIOR 2007, L1 Norm, Paper Introduces Deviation, Soft Global Constraint