x          z   a   b
0.34679014 N/A pan pan
0.75867996 N/A eks pan
0.20460331 N/A N/A wye
0.38139939 N/A eks N/A
N/A        N/A wye pan
0.52712616 N/A zee pan
0.61178406 N/A eks zee
0.59855401 N/A zee wye
0.03144188 N/A N/A N/A
0.50262601 N/A pan wye
