Regularity of parametric interval matrices

A *parametric interval matrix* is a matrix whose elements are
functions of unknowns whose values lie in some pre-defined ranges. It
is therefore a matrix that has a higher structure than the classical
interval matrix (i.e. matrices whose elements are intervals) as there
may be dependency between the elements of the matrix.

A sophisticated procedure to check for the regularity of a parametric matrix is based on the following scheme: the sign of the determinant is calculated for a point value of the input parameters (say positive), then the algorithm try to find another input value such that the sign of the corresponding determinant is negative.

Jean-Pierre Merlet 2012-12-20