find_ql_diff function

Convert index into group pair in tauDown_Q

This function is the inverse of the conversion ${(q,l), q<l}$ into ${1,...,Q*(Q-1)/2}$. Used only in tauDown_Q.

find_ql_diff(ind_ql, Q)

Arguments

• ind_ql: Converted $(q,l)$ index
• Q: Total number of groups $Q$

Returns

Group pair $(q,l)$ corresponding to the given index