Changeset c9fc873 in sasmodels

Ignore:
Timestamp:
Jul 9, 2018 7:13:35 AM (12 months ago)
Branches:
master, core_shell_microgels, magnetic_model, ticket-1257-vesicle-product, ticket_1156, ticket_1265_superball, ticket_822_more_unit_tests
Children:
c11d09f
Parents:
751da81
Message:

normalise R_g in guinier docs; use 'SLD centre of mass'

File:
1 edited

Legend:

Unmodified
 r751da81 In scattering, the radius of gyration $R_g$ quantifies the objects's distribution of SLD (not mass density, as in mechanics) from the objects's centre of mass. It is defined by SLD centre of mass. It is defined by .. math:: R_g^2 = \sum_i^\text{all points}\rho_i\left(r_i-r_0\right)^2 .. math:: R_g^2 = \frac{\sum_i\rho_i\left(r_i-r_0\right)^2}{\sum_i\rho_i} where $r_0$ denotes the object's centre of mass and $\rho_i$ is the SLD at a point $i$. where $r_0$ denotes the object's SLD centre of mass and $\rho_i$ is the SLD at a point $i$. Notice that $R_g^2$ may be negative (since SLD can be negative), which happens