def v1(self):
        """Return voltage phasors at the "from buses" (bus1)"""
        Vm = self.system.dae.y[self.v]
        Va = self.system.dae.y[self.a]
        return polar(Vm[self.a1], Va[self.a1])
def v1 ( self ) : Vm = self . system . dae . y [ self . v ] Va = self . system . dae . y [ self . a ] return polar ( Vm [ self . a1 ] , Va [ self . a1 ] )
Return voltage phasors at the "from buses" (bus1)