Low-level helper functions for computing sums, cumulative sums, and reverse cumulative sums within strata groups, as well as matrix double-indexing.
Usage
sumstrata(x, strata, nstrata)
cumsumstrata(x, strata, nstrata)
revcumsumstrata(x, strata, nstrata)
revcumsum(x)
matdoubleindex(x, rows, cols, xvec = NULL)
mdi(x, ...)Arguments
- x
numeric vector (or matrix for
matdoubleindex).- strata
integer vector of strata indices (0-based).
- nstrata
number of distinct strata.
- rows
row indices for
matdoubleindex.- cols
column indices for
matdoubleindex.- xvec
optional values to assign at indexed positions.
- ...
additional arguments (for
mdi).