14. A method according to claim 11 , further comprising: providing a further compass within the two-dimensional display.
14. A method according to claim 11 , further comprising: providing a further compass within the two-dimensional display. 15. A method according to claim 14 , further comprising: determining the spine labels for the compass and the further compass, comprising: generating a set of spine labels for the cluster spines that appear within one of the compasses that is concentric to the other compass; and generating a different set of spine labels for those cluster spines that appear only within the other compass.