Usage
fast_aggregate(x, groupings = NULL, form = NULL, fun = "sum", ...)
Arguments
- x
A matrix. Dense inputs are coerced to a sparse matrix.
- groupings
Group labels, recycled to a one-column data frame.
- form
Optional model formula used to build the grouping design.
- fun
Aggregation: `"sum"`, `"mean"`, or `"count"`.
- ...
Unused.
Value
A sparse matrix with groups in rows.
Examples
fast_aggregate(
matrix(1:6, nrow = 3),
groupings = c("a", "a", "b"),
fun = "sum"
)
#> 2 x 2 sparse Matrix of class "dgCMatrix"
#>
#> a 3 9
#> b 3 6
