def set_frame(self, fast_axis, slow_axis, origin):
''' Set the local frame.
Sets its own global plane and then, after updating its local
frame, propagates the frame down to its children.
:param fast_axis: The fast axis of the virtual detector plane
:param slow_axis: The slow axis of the virtual detector plane
:param origin: The origin vector to the virtual detector plane
'''
VirtualPanel.set_frame(self, fast_axis, slow_axis, origin)
for child in self:
child.set_parent_frame(
self.get_fast_axis(),
self.get_slow_axis(),
self.get_origin())
