System Specification by Impedance Based Linear Graph

In the example below, a parallel tuned electrical R-L-C circuit is specified to SYREP by the impedances between the numbered nodes on an impedance graph.  

    In this example there is a series R-L impedance, Z = R_L + sL, representing a lumped inductance L and resistance R_L of a coil between nodes 2 and 3.  The branch is specified to SYREP as a list: [2,3,impedance,R_L+s*L].   Branch relationships may also be expressed as admittances, for example the capacitor is expressed as Y = sC in the example.  Variable names associated with the branch variables may be optionally specified.  In this example the capacitor voltage and current names are specified, so that they may be used as named output variables.
   Maple SYREP constructs a phase-variable system object named "Tuned_circuit" from the graph structure.
   In this example, the transfer function is displayed, the damping ratio and undamped natural frequency are computed, and the circuit's frequency response magnitude is presented using the SYREP procedure Bode_magnitude().