Calculate timesteps in days

Usage

mm_get_timestep(
  datetimes,
  format = c("mean", "unique", "modal"),
  require_unique = FALSE,
  tol = 60/(24 * 60 * 60)
)

Arguments

datetimes: A POSIXct vector from which to calculate timesteps.
format: A string specifying the output format. "mean" always returns one value; "unique" may return more than one, depending on the variation in timesteps and the value of tol.
require_unique: A logical. Should exactly one unique timestep (within the tolerance tol) be required?
tol: If format = "unique", the minimum difference in days for two timesteps to be considered distinct. For example, 1 / (24 * 60 * 60) is one second.

Value

A numeric vector of timesteps in days. Its length depends on format.

Examples

datetimes <- Sys.time() +
  as.difftime(c(0, 304, 600, 900.2, 1200, 1500, 1800), units = "secs")
mm_get_timestep(datetimes, "unique", tol = 1 / (24 * 60 * 60))
#> [1] 0.003425926 0.003469907 0.003518519
mm_get_timestep(datetimes, "unique", tol = 5 / (24 * 60 * 60))
#> [1] 0.003425926 0.003518519
mm_get_timestep(datetimes, "mean")
#> [1] 0.003472222
mm_get_timestep(
  datetimes,
  "mean",
  require_unique = TRUE,
  tol = 300 / (24 * 60 * 60)
)
#> [1] 0.003425926

datetimes <- Sys.time() +
  as.difftime(c(-1, 0, 2, 4, 5, 6, 8, 10), units = "days")
mm_get_timestep(datetimes, "modal")
#> [1] 2
mm_get_timestep(c(), "mean")
#> [1] NA

try(mm_get_timestep(datetimes, "mean", require_unique = TRUE))
#> Error in mm_get_timestep(datetimes, format = "unique", require_unique = TRUE,  : 
#>   Found 2 unique timesteps; expected exactly one.
try(mm_get_timestep(c(), "unique", require_unique = TRUE))
#> Error in mm_get_timestep(c(), "unique", require_unique = TRUE) : 
#>   Could not determine exactly one unique timestep.