GRTBactrianScaleOperator ======================== .. java:class:: public tyche.evolution.operator.GRTBactrianScaleOperator :inheritance: beast.base.evolution.operator.kernel.BactrianScaleOperator BactrianScaleOperator that will handle rootOnly scale appropriately if the provided Tree is a GermlineRootTree .. java:method:: public double doGRTProposal() handle rootOnly scale appropriately if the provided Tree is a GermlineRootTree .. java:method:: public double proposal() Change the parameter. :return: Double.NEGATIVE_INFINITY if proposal should not be accepted