Count observations by group

Usage

count(x, ..., wt = NULL, sort = FALSE, name = NULL)

tally(x, wt = NULL, sort = FALSE, name = NULL)

Arguments

x: A vectra_node object.
...: Grouping columns, resolved as in group_by().
wt: Column to weight by (unquoted). If NULL, counts rows.
sort: If TRUE, sort output in descending order of n.
name: Name of the count column (default "n").

Value

A vectra_node with group columns and a count column.

Details

Equivalent to group_by(...) |> summarise(n = n()). When wt is provided, uses sum(wt) instead of n(). When sort = TRUE, results are sorted in descending order of the count column.

Examples

f <- tempfile(fileext = ".vtr")
write_vtr(mtcars, f)
tbl(f) |> count(cyl) |> collect()
unlink(f)