`count()` lets you quickly count the unique values of one or more variables: `df `df `count()` is paired with `tally()`, a lower-level helper that is equivalent to `df switching the summary from `n = n()` to `n = sum(wt)`.
`add_count()` are `add_tally()` are equivalents to `count()` and `tally()` but use `mutate()` instead of `summarise()` so that they add a new column with group-wise counts.
count(
x,
...,
wt = NULL,
sort = FALSE,
name = NULL,
.drop = group_by_drop_default(x)
)
add_count(
x,
...,
wt = NULL,
sort = FALSE,
name = NULL,
.drop = group_by_drop_default(x)
)
# S3 method for default
add_count(
x,
...,
wt = NULL,
sort = FALSE,
name = NULL,
.drop = group_by_drop_default(x)
)
# S3 method for Seurat
add_count(
x,
...,
wt = NULL,
sort = FALSE,
name = NULL,
.drop = group_by_drop_default(x)
)
A data frame, data frame extension (e.g. a tibble), or a lazy data frame (e.g. from dbplyr or dtplyr).
<[`data-masking`][dplyr_data_masking]> Variables to group by.
<[`data-masking`][dplyr_data_masking]> Frequency weights. Can be `NULL` or a variable:
* If `NULL` (the default), counts the number of rows in each group. * If a variable, computes `sum(wt)` for each group.
If `TRUE`, will show the largest groups at the top.
The name of the new column in the output.
If omitted, it will default to `n`. If there's already a column called `n`, it will error, and require you to specify the name.
For `count()`: if `FALSE` will include counts for empty groups (i.e. for levels of factors that don't exist in the data). Deprecated in `add_count()` since it didn't actually affect the output.
An object of the same type as `.data`. `count()` and `add_count()` group transiently, so the output has the same groups as the input.