Radius of gyration calculator

This Javascript calculates the Radius of Gyration of concentric shell models. Enter the number of shells, the lengths of the respective semi-axis Rx(i), Ry(i) and Rz(i) (z is in the axis of rotation) and the corresponding electron-density c(i) between R(i-1) <= R(i). The values of the radius of gyration Rg and of the zero-angle intensity I(0), respectively, will be calculated. Units are arbitrary and in metric dimensions (usually in Å or nm). In case of models extending infinitely in the 3rd dimension, Rg of the cross-section (circle, ellipse or rectangle, Rz is set to 0), and in case of models spreading infinitely in two dimensions, Rg of the thickness (line, Rx and Ry are set to 0) will be calculated, respectively. In case of a torus, Rz is defined as the semi-axis of the torus (Rzb/Rza ratio of the two semi-axes), with the semi-axes of the tubular cross-section (o: round, #:rectangular) of the torus Rx(i) parallel to Rz and Ry(i) normal to Rz.