a   b   i  x          y          i_shift_lag_2 i_shift_lead_2
eks pan 2  0.75867996 0.52215111 -             7
eks wye 4  0.38139939 0.13418874 -             -
eks zee 7  0.61178406 0.18788492 2             -
pan pan 1  0.34679014 0.72680286 -             -
pan wye 10 0.50262601 0.95261836 -             -
wye wye 3  0.20460331 0.33831853 -             -
wye pan 5  0.57328892 0.86362447 -             -
zee pan 6  0.52712616 0.49322129 -             -
zee wye 8  0.59855401 0.97618139 -             -
