  We investigate positive definiteness, Hurwitz stability and Schur stability
of parametric interval matrices. We give a verifiable sufficient condition for
positive definiteness of parametric interval matrices with non-linear
dependencies. We also give several sufficient and necessary conditions for
stability of symmetric parametric interval matrices with affine-linear
dependencies. The presented results extend the results on positive definiteness
and stability of interval matrices. In addition, we provide a formula for the
radius of stability of symmetric parametric interval matrices.
