Fractional analysis is to analyse axial map where topological step between pairs of the lines are not 1, but weighted by angular change between them.
Space Syntax Glossary
Dalton, N. (2001), Fractional Configurational Analysis and A Solution to the Manhattan Problem. In: Proceedings of 3rd International Space Syntax Symposium Atlant 2001, 26.01-26.13. pp.26.7