objref zz
zz = new Impedance()
func rn() { local rn
init() // make sure all changes to g, c, ri etc. have taken effect
soma zz.loc(0.5) // sets origin for impedance calculations to middle of soma
zz.compute(0) // DC input R
soma { rn = zz.input(0.5) } // rn is input R at middle of the soma
return rn
}