def get_tip_coordinates(self, axis=None):
<EOL>coords = self.get_node_coordinates()<EOL>if axis == '<STR_LIT:x>':<EOL><INDENT>return coords[:self.ntips, <NUM_LIT:0>]<EOL><DEDENT>elif axis == '<STR_LIT:y>':<EOL><INDENT>return coords[:self.ntips, <NUM_LIT:1>]<EOL><DEDENT>return coords[:self.ntips]<EOL>
Returns coordinates of the tip positions for a tree. If no argument
for axis then a 2-d array is returned. The first column is the x 
coordinates the second column is the y-coordinates. If you enter an 
argument for axis then a 1-d array will be returned of just that axis.