def _set_namespace(self, namespaces):
        """Set the name space for use when calling eval. This needs to contain all the relvant functions for mapping from symbolic python to the numerical python. It also contains variables, cached portions etc."""
        self.namespace = {}
        for m in namespaces[::-1]:
            buf = _get_namespace(m)
            self.namespace.update(buf)
        self.namespace.update(self.__dict__)