Filters a time series of incidence data to only include rows within a specified date range.
Examples
df <- data.frame(date_ymd = seq.Date(as.Date("2020-01-01"), by = "day", length.out = 100),
incidence = rpois(100, 5))
filtered <- filter_incidence_by_dates(df, c("2020-01-10", "2020-01-20"))