Blocked Infinity Sparse Matrix
Source:R/InfinitySparseMatrix.R
      BlockedInfinitySparseMatrix-class.RdBlocked Infinity Sparse Matrices are similar to Infinity Sparse Matrices, but they also keep track of the groups of units via an additional slot, groups
Slots
groupsfactor vector containing groups, with unit names as labels, when possible
colnamesvector containing names for all control units. This will either be a character vector or NULL if units have no names
rownamesvector containing names for all treated units. This will either be a character vector or NULL if units have no names
colsvector of integers corresponding to control units
rowsvector of integers corresponding to treated units
dimensioninteger vector containing the number of treated and control units, in that order
callfunction call used to create the
InfinitySparseMatrix