The characteristics equation can be induced by the state equation or the transfer function of the system, but it does not correspond with input parameters in the system, so that it can not be obtained without the modification of the system.
As the ex...
The characteristics equation can be induced by the state equation or the transfer function of the system, but it does not correspond with input parameters in the system, so that it can not be obtained without the modification of the system.
As the extension of Mason's formula in Signal-flow graph can be represented the gain of one node to another, the characteristics equation of the system would be more easily obtained in Signal-flow graph.