 th-order matrix constrained by the specification of certain zero entries. This problem finds applications in many areas, but it was originally motivated by attempts to obtain desired responses from an
 th-order matrix constrained by the specification of certain zero entries. This problem finds applications in many areas, but it was originally motivated by attempts to obtain desired responses from an  th-order dynamic system governed by a set of linear homogeneous differential equations of the form
 th-order dynamic system governed by a set of linear homogeneous differential equations of the form  where
 where  is the constant real system matrix to be found.
 is the constant real system matrix to be found.