keep_first()
and keep_last()
keep the first and last n
rows to occur
for each grouping when in ascending date order. keep_peaks()
keeps the rows
with the maximum count value for each group.
Usage
keep_first(x, n, complete_dates = TRUE, ...)
keep_last(x, n, complete_dates = TRUE, ...)
keep_peaks(x, complete_dates = TRUE, first_only = FALSE, ...)
Arguments
- x
<incidence2>
object.- n
[integer]
Number of entries to keep.
double
vectors will be converted viaas.integer(n)
.- complete_dates
[bool]
Should
complete_dates()
be called on the data prior to keeping the first entries.Defaults to TRUE.
- ...
Other arguments passed to
complete_dates()
.- first_only
[bool]
Should only the first peak (by date) be kept.
Defaults to
TRUE
.
Examples
data.table::setDTthreads(2)
if (requireNamespace("outbreaks", quietly = TRUE)) {
withAutoprint({
data(ebola_sim_clean, package = "outbreaks")
dat <- ebola_sim_clean$linelist
inci <- incidence(dat, "date_of_onset")
keep_first(inci, 3)
keep_last(inci, 3)
})
}
#> > data(ebola_sim_clean, package = "outbreaks")
#> > dat <- ebola_sim_clean$linelist
#> > inci <- incidence(dat, "date_of_onset")
#> > keep_first(inci, 3)
#> # incidence: 3 x 3
#> # count vars: date_of_onset
#> date_index count_variable count
#> * <date> <chr> <int>
#> 1 2014-04-07 date_of_onset 1
#> 2 2014-04-08 date_of_onset 0
#> 3 2014-04-09 date_of_onset 0
#> > keep_last(inci, 3)
#> # incidence: 3 x 3
#> # count vars: date_of_onset
#> date_index count_variable count
#> * <date> <chr> <int>
#> 1 2015-04-28 date_of_onset 8
#> 2 2015-04-29 date_of_onset 2
#> 3 2015-04-30 date_of_onset 2