The pair correlation function (pCF) is a set of cross-correlations between the central fiber and all fibers located at a given distance from the center. For a better signal to noise ratio, cross-correlations are calculated in both directions and then averaged. The pCFs are used and displayed in the polar heatmaps of the Diffusion view.

The Diffusion view can display the data of two different sets of fibers. The group called Outer Elements comprises fibers with a slightly bigger distance from the center (blue element) and is illustrated with orange in the graphic below. The second group is called Inner Elements and comprises fibers with a slightly smaller distance from the center. They are illustrated with the green color in the graphic below.

Fiber Group	Fibers
Outer Elements	Comprises fibers 9, 11, 13, 15, 17 and 19.
Inner Elements	Comprises fibers 8, 10, 12, 14, 16 and 18.