Extend/contract mts time series to new start and end times

Source: R/mts_setTimeAxis.R

Extends or contracts the time range of an mts object by adding/removing time steps at the start and end and filling any new time steps with missing values. The resulting time axis is guaranteed to be a regular, hourly axis with no gaps using the same timezone as the incoming mts object. This is useful when you want to place separate mts objects on the same time axis for plotting.

Dates can be anything that is understood by MazamaCoreUtils::parseDatetime() including either of the following recommended formats:

  • "YYYYmmdd"

  • "YYYY-mm-dd"

Timezone determination precedence assumes that if you are passing in POSIXct values then you know what you are doing:

  1. get timezone from startdate if it is POSIXct

  2. use passed in timezone

  3. get timezone from mts

If either startdate or enddate is missing, the start or end of the timeseries in mts will be used.

If neither startdate nor enddate is a POSIXct value AND no timezone is supplied, the timezone will be inferred from the most common timezone found in mts.

mts_setTimeAxis(mts = NULL, startdate = NULL, enddate = NULL, timezone = NULL)

Arguments

mts

mts object.

startdate

Desired start date (ISO 8601).

enddate

Desired end date (ISO 8601).

timezone

Olson timezone used to interpret startdate and enddate.

Value

The incoming mts time series object defined on a new time axis. (A list with meta and data dataframes.)

Examples

library(MazamaTimeSeries)

# Default range
range(example_mts$data$datetime)
#> [1] "2019-07-01 07:00:00 UTC" "2019-07-08 06:00:00 UTC"

# One-sided extend with user specified timezone
example_mts %>%
  mts_setTimeAxis(enddate = 20190815, timezone = "UTC") %>%
  mts_extractData() %>%
  dplyr::pull(datetime) %>%
  range()
#> [1] "2019-07-01 07:00:00 UTC" "2019-08-15 00:00:00 UTC"

# Two-sided extend with user specified timezone
example_mts %>%
  mts_setTimeAxis(20190615, 20190815, timezone = "UTC") %>%
  mts_extractData() %>%
  dplyr::pull(datetime) %>%
  range()
#> [1] "2019-06-15 UTC" "2019-08-15 UTC"

# Two-sided extend without timezone (uses timezone from mts$meta$timezone)
example_mts %>%
  mts_setTimeAxis(20190615, 20190815) %>%
  mts_extractData() %>%
  dplyr::pull(datetime) %>%
  range()
#> [1] "2019-06-15 07:00:00 UTC" "2019-08-15 07:00:00 UTC"