On the calculation of the transfer function matrix

Given the state space realization
\{A,B,C\}
of a linear time-invariant multivariable dynamic system, a computational algorithm for calculating elements of the corresponding transfer function matrix is presented. The algorithm neither requires cofactor calculation, nor applies any state transformation. The only requirement is calculation of the coefficients of characteristic equations of given matrices. Also, the Fortran subroutine based on the presented algorithm is included.