From a spacetime
object, activate either the data or geometry contexts. The active object will then become available for manipulation.
Arguments
- .data
a spacetime object
- what
default NULL. Determines which context to activate. Valid argument values are
"geometry"
and"data"
. If left null, returns.data
.
Value
For activate()
an object of class spacetime with the specified context activated. active()
returns a scalar character with the active context can be either "goemetry" or "data".
Details
A spacetime
object contains both a data frame and an sf object. The
data frame represents geographies over one or more time periods and the sf
object contains the geographic information for those locations.
Examples
df_fp <- system.file("extdata", "bos-ecometric.csv", package = "sfdep")
geo_fp <- system.file("extdata", "bos-ecometric.geojson", package = "sfdep")
# read in data
df <- readr::read_csv(df_fp, col_types = "ccidD")
geo <- sf::read_sf(geo_fp)
# Create spacetime object called `bos`
bos <- spacetime(df, geo,
.loc_col = ".region_id",
.time_col = "time_period")
active(bos)
#> [1] "data"
activate(bos, "geometry")
#> spacetime ────
#> Context:`geometry`
#> 168 locations `.region_id`
#> 10 time periods `time_period`
#> ── geometry context ────────────────────────────────────────────────────────────
#> Simple feature collection with 168 features and 1 field
#> Geometry type: POLYGON
#> Dimension: XY
#> Bounding box: xmin: -71.19115 ymin: 42.22788 xmax: -70.99445 ymax: 42.3974
#> Geodetic CRS: NAD83
#> # A tibble: 168 × 2
#> .region_id geometry
#> * <chr> <POLYGON [°]>
#> 1 25025010405 ((-71.09009 42.34666, -71.09001 42.34668, -71.08941 42.34685, -7…
#> 2 25025010404 ((-71.09066 42.33977, -71.09103 42.33961, -71.09177 42.33989, -7…
#> 3 25025010801 ((-71.08159 42.3537, -71.08044 42.35402, -71.07995 42.35415, -71…
#> 4 25025010702 ((-71.07066 42.35185, -71.07045 42.35142, -71.07282 42.35075, -7…
#> 5 25025010204 ((-71.10683 42.34875, -71.1052 42.34844, -71.10468 42.34834, -71…
#> 6 25025010802 ((-71.08159 42.3537, -71.08153 42.35358, -71.08145 42.3534, -71.…
#> 7 25025010104 ((-71.08784 42.34746, -71.08805 42.34746, -71.0883 42.34747, -71…
#> 8 25025000703 ((-71.12622 42.35041, -71.12685 42.35009, -71.12748 42.35, -71.1…
#> 9 25025000504 ((-71.14175 42.3404, -71.14194 42.34001, -71.14234 42.34005, -71…
#> 10 25025000704 ((-71.13551 42.34878, -71.13572 42.34904, -71.1358 42.34917, -71…
#> # … with 158 more rows
#> # ℹ Use `print(n = ...)` to see more rows