Tracking collective cell motion by topological data analysis
Fig 24
For the expanding strip in (a), we get the Betti numbers b0 for the upper front (b), and for the lower one (c).
The lower front is rougher (larger b0) but its fingers are shorter (b0 decays faster to one and zero), whereas the upper front has a dominant persistent finger. We have set rmax = 1 mm in the scale of the image Fig 4. S22 and S23 Data have been used to draw this figure.