absolute concentration values not matching with other open-source options?

I've been struggling with the concentration indexes (especially the ACO), because I'm trying to match the values with the ones that is generated by OasisR (https://cran.r-project.org/web/packages/OasisR/OasisR.pdf)... in the original paper of OasisR the author (page 12, Table 6) states that this index matches the one of the GSA implementations.

However, I'm closely checking line by line of the functions and am not seeing any difference of the R implementation (https://github.com/cran/OasisR/blob/99f5d028c205329c4f3b1355e5bcaa09e1fcc077/R/SegFunctions.R#L1358) and our implementation. I highlight that the R and GSA implementation might be not correct, but I wanted to open a discussion of this.

The original formula is:

To reproduce this in Python (edit path needed):

import geopandas as gpd
import segregation
from segregation.spatial import Absolute_Concentration

irreg = gpd.read_file('C:\\Users\\renan\\Desktop\\oasisTests\\irregular_lattice_50.shp')
irreg['group_pop_var'] = list(range(1, 51))
irreg['total_pop_var'] = 100
index1 = Absolute_Concentration(irreg, 'group_pop_var', 'total_pop_var')
index1.statistic

to reproduce this in R (edit path needed):

library(OasisR)
library(rgdal)
irreg<-readOGR("C:\\Users\\renan\\Desktop\\oasisTests","irregular_lattice_50")
vector1 <- seq(1,50) # Group 1 Population
tot <- rep(100, 50)
vector2 <- tot - vector1 # Group 2 Population
irreg_input_data <- cbind(vector1, vector2)
ACO(irreg_input_data, spatobj = irreg)
# The first value is the ACO value for the first group

The irregular lattice used is attached. irregular_lattice_50.zip

pysal / segregation

absolute concentration values not matching with other open-source options? #43