The Rows Gini index concentrates on the "relative extent
to which the destination selections of out-migrations are
spatially focused": $$G^T_R = \frac{\sum_i \sum_{j
\neq i} \sum_{h \neq i,j} | M_{ij} - M_{ih} | }{
(2n(n-1)-1) \sum_i \sum_{j \neq i} M_{ij}}$$ This
implementation solves the above formula by computing the
dist matrix for each row.
Usage
migration.gini.row(m)
Arguments
m
migration matrix
Value
A number between 0 and 1 where 0 means no spatial
focusing and 1 shows maximum focusing.
References
David A. Plane and Gordon F. Mulligan
(1997) Measuring Spatial Focusing in a Migration System.
Demography34, 251--262