Create a new s2_cell_dates (s2cd) vector

A s2cd vector (short for s2_cell_dates) stores an s2::s2_cell vector alongside a list of date vectors, where each vector of chronologically, non-missing dates corresponds to each valid, level 30 s2 cell. Create a new s2cd vector with s2cd() or coerce another object into a s2cd vector with as_s2cd().

Usage

s2cd(.data, dates = list(), sort_dates = FALSE)

Arguments

.data

an s2_cell vector that is valid and is at level 30 resolution

dates

a list of date vectors, each in chronological order and without missing values

sort_dates

logical; sort each date vector chronologically when needed. This defaults to FALSE so accidentally unordered dates continue to error.

Value

A s2cd vector

Details

Each position in the s2_cells vector corresponds to the same-indexed element in dates, allowing multiple dates to be associated with a single level-30 S2 cell.

At level 30, S2 cells have an approximate spatial resolution of 1 centimeter; in this context, they are intended to function as point-like representations rather than true spatial areas.

See also

as_s2cd

Examples

# create directly with s2_cell vector and list of Date vectors
d <- s2cd(
  s2::as_s2_cell(c("8841b39a7c46e25f", "8841a45555555555")),
  dates = list(
    as.Date("2026-01-01"),
    c(as.Date("2024-09-13"), as.Date("2024-09-20"))
  )
)

# check if d is a s2cd vector
is_s2cd(d)
#> [1] TRUE

# use a s2cd vector as a tibble column
# the display includes each cell's number of dates
tibble::tibble(id = seq_along(d), location = d)
#> # A tibble: 2 × 2
#>      id location           
#>   <int> <s2cd>             
#> 1     1 8841b39a7c46e25f[1]
#> 2     2 8841a45555555555[2]

# create using data.frame with s2_cell and dates columns
data.frame(
  s2_cell = s2::as_s2_cell(c("8841b39a7c46e25f", "8841a45555555555")),
  dates = I(list(
    as.Date("2026-01-01"),
    c(as.Date("2024-09-13"), as.Date("2024-09-20"))
  ))
) |>
  as_s2cd()
#> <s2_cell_dates[2]>
#> [1] 8841b39a7c46e25f[1] 8841a45555555555[2]