How does AIQ calculate the groups and sectors?

1st day of the index:
Close – stocks
current close / prior close = ratio
summation of all ratios / # of stocks
in group * groups prior close (should be 100).

After 1st day: summation of all ratios / # stocks in
group * groups prior close

High, low and open: (example for high)
current high / current close = ratio
summation of all ratios / # of stocks
in group * current close for the group.