| fill_gap {statar} | R Documentation | 
Add rows corresponding to gaps in some variable
Description
Add rows corresponding to gaps in some variable
Usage
fill_gap(
  x,
  ...,
  full = FALSE,
  roll = FALSE,
  rollends = if (roll == "nearest") c(TRUE, TRUE) else if (roll >= 0) c(FALSE, TRUE) else
    c(TRUE, FALSE)
)
Arguments
| x | A data frame | 
| ... | a time variable | 
| full | A boolean. When full = FALSE (default), the function creates rows corresponding to all missing times between the min and max of  | 
| roll | When roll is a positive number, values are carried forward. roll=TRUE is equivalent to roll=+Inf. When roll is a negative number, values are rolled backwards; i.e., next observation carried backwards (NOCB). Use -Inf for unlimited roll back. When roll is "nearest", the nearest value is used. Default to FALSE (no rolling) | 
| rollends | A logical vector length 2 (a single logical is recycled). When rolling forward (e.g. roll=TRUE) if a value is past the last observation within each group defined by the join columns, rollends[2]=TRUE will roll the last value forwards. rollends[1]=TRUE will roll the first value backwards if the value is before it. If rollends=FALSE the value of i must fall in a gap in x but not after the end or before the beginning of the data, for that group defined by all but the last join column. When roll is a finite number, that limit is also applied when rolling the end | 
Examples
library(dplyr)
library(lubridate)
df <- tibble(
    id    = c(1, 1, 1, 1),
    datem  = as.monthly(mdy(c("01/01/1992", "02/01/1992", "04/01/1992", "7/11/1992"))),
    value = c(4.1, 4.5, 3.3, 3.2)
)
df %>% group_by(id) %>% fill_gap(datem)
df %>% group_by(id) %>% fill_gap(datem, roll = 1)
df %>% group_by(id) %>% fill_gap(datem, roll = "nearest")
df %>% group_by(id) %>% fill_gap(datem, roll = "nearest", full = TRUE)