In this work an alternative to the analysis of the Fukui function will be presented and compared with the traditional condensed function. The topological analysis allows us to define basins corresponding to different regions of the space, and the numerical integration of the density over those volumes gives a number amenable of a chemical interpretation in line with the Fukui function applications. Various examples are shown, a series of small molecules, a couple of clusters, and aromatic molecules. They are discussed in comparison with other methodologies and with the experimental evidence.