International
Tables for
Crystallography
Volume C
Mathematical, physical and chemical tables
Edited by E. Prince

International Tables for Crystallography (2006). Vol. C, ch. 2.6, p. 91

Figure 2.6.1.1 

O. Glattera
[Figure 2.6.1.1]
Figure 2.6.1.1

The height of the p(r) function for a certain value of r is proportional to the number of lines with a length between r and r + dr within the particle.