Help! How to simulate transmission gate's on-resistance in Hspice?

雪芙女神

.DC Vin 0 3.3 0.001
.probe dc Rp=par('(V(Vout)-V(Vin))/i(M1)')+Rn=par('(V(Vin)-V(Vout))/i(M2)')+Ron_eq=par('((V(Vout)-V(Vin))/i(M1))*((V(Vin)-V(Vout))/i(M2))/(((V(Vout)-V(Vin))/i(M1))+((V(Vin)-V(Vout))/i(M2)))')

change polarity if needed!