I calculated natural break clustering in each GIS software and Python Jenkspy library.
The data is population of each city in Europe and this is the result below.
Jenkspy library and QGIS shows somewhat similar results (but not really) while other trials return totally different results.
I am going to try with CartoDB PostGIS Extension though, I am already doubting the result.
the input data is all same and I made 6 classes for division. But I am not understanding why the results are different.
Does anyone know the reasons?