R: A shorthand for filtering time index for a tsibble

filter_index {tsibble} | R Documentation

## A shorthand for filtering time index for a tsibble

### Description

This shorthand respects time zones and encourages compact expressions.

### Usage

    filter_index(.data, ..., .preserve = FALSE)

### Arguments

`.data` | A tsibble.
`...` | Formulas that specify start and end periods (inclusive) or strings. `~ end` or `. ~ end`: from the very beginning to a specified ending period. `start ~ end`: from specified beginning to ending periods. `start ~ .`: from a specified beginning to the very end of the data. Supported index type: `POSIXct` (to seconds), `Date`, `yearweek`, `yearmonth`/`yearmon`, `yearquarter`/`yearqtr`, `hms`/`difftime` & `numeric`.
`.preserve` | when `FALSE` (the default), the grouping structure is recalculated based on the resulting data, otherwise it is kept as is.

### System Time Zone ("Europe/London")

There is a known issue of an extra hour gained for a machine setting time zone to "Europe/London", regardless of the time zone associated with the POSIXct inputs. It relates to anytime and Boost. Use `Sys.timezone()` to check if the system time zone is "Europe/London". It would be recommended to change the global environment "TZ" to other equivalent names: GB, GB-Eire, Europe/Belfast, Europe/Guernsey, Europe/Isle_of_Man and Europe/Jersey as documented in `?Sys.timezone()`, using `Sys.setenv(TZ = "GB")` for example.

### See Also

time_in for a vector of time index

### Examples

    # from the starting time to the end of Feb, 2015
    pedestrian %>%
      filter_index(~ "2015-02")

    # entire Feb 2015, & from the beginning of Aug 2016 to the end
    pedestrian %>%
      filter_index("2015-02", "2016-08" ~ .)

    # multiple time windows
    pedestrian %>%
      filter_index(~ "2015-02", "2015-08" ~ "2015-09", "2015-12" ~ "2016-02")

    # entire 2015
    pedestrian %>%
      filter_index("2015")

    # specific
    pedestrian %>%
      filter_index("2015-03-23" ~ "2015-10")
    pedestrian %>%
      filter_index("2015-03-23" ~ "2015-10-31")
    pedestrian %>%
      filter_index("2015-03-23 10" ~ "2015-10-31 12")

[Package tsibble version 0.8.2 Index]