def changeUnit(self, unit):
#save old unit
oldunit = self.unit()
#use parent class's changeUnit, but please remember:
if self.__isslice:
msg = "This axis %r is a slice. cannot change unit." % self.name()
raise RuntimeError, msg
#there is a problem with mapper!!!!
Dataset.changeUnit(self, unit)
#mapper need to be reset
self._mapper = createMapper( self._storage.asList(), self._mapper.__class__ )
#!!! need to remove cache!!!
self._cache = {}
#also need to update centers if necssary
if self._centers is not None:
self._centers = N.array(self._centers) * (oldunit/self.unit())
return
