Compute the GPIC index as described in Pham (2020) 10.35542/osf.io/ajz5v.
GPIC index reflects both the quantity and quality of
prizes that a group of participants obtained in individual competitions.
Call vec2idx and df2idx to compute GPIC index
for a single group and multiple groups, respectively. The results of
Vietnamese National Olympiads are provided as sample datasets
vno and vnomath.
GPIC: Quantifying Group Performance in Individual Competitions. Copyright (C) 2021 Duy Nghia Pham GPIC is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. GPIC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GPIC. If not, see https://www.gnu.org/licenses/.