def update_Mix(self):
        kwds = dict(
            Vfrac=self.Vfrac,  #vfrac because don't want it to reset to default
            solutematerial=self.Material1,
            solventmaterial=self.Material2)

        if self.MixingStyle == 'MG (root)':
            self.Mix = MG(**kwds)

        elif self.MixingStyle == 'Bruggeman (root)':
            self.Mix = Bruggeman(**kwds)

        elif self.MixingStyle == 'QCACP (root)':
            self.Mix = QCACP(**kwds)

        elif self.MixingStyle == 'MG Garcia':
            self.Mix = MG_Mod(**kwds)

        elif self.MixingStyle == 'LinearSum':
            self.Mix = LinearSum(**kwds)

        # I think because I'm delegating mixedarray, but for some reason DoubleMixer.__init__
        # trigger doesn't hook up right.  Should not have to do this, but doesn't
        # cost much extra so don't mess with it.  Exhausted all posib
        self.Mix.update_mix()
 def _Mix_default(self):
     return LinearSum(solutematerial=self.Material1,
                      solventmaterial=self.Material2)