Get, set, or replace time information

Usage

st_time(obj, ...)

st_time(x, ...) <- value

# S3 method for class 'sftime'
st_time(obj, ...)

# S3 method for class 'sf'
st_time(x, ..., time_column_name = "time") <- value

# S3 method for class 'sftime'
st_time(x, ...) <- value

st_set_time(x, value, ...)

st_drop_time(x)

Arguments

obj: An object of class sftime.
...: Additional arguments; Ignored.
x: An object of class sftime or sf.
value: An object for which is_sortable returns TRUE or an object of class character, or NULL.
time_column_name: Character value; The name of the column to set as active time column in x.

Value

st_time returns the content of the active time column of an sftime object. Assigning an object for which is_sortable returns TRUE to an sf object creates an sftime object. Assigning an object for which is_sortable returns TRUE to an sftime object replaces the active time column by this object.

Details

In case value is character and x is of class sftime, the active time column (as indicated by attribute time_column) is set to x[[value]].

The replacement function applied to sftime objects will overwrite the active time column, if value is NULL, it will remove it and coerce x to an sftime object.

st_drop_time drops the time column of its argument, and reclasses it accordingly.

Examples

# from sftime object
g <- st_sfc(st_point(1:2))
time <- Sys.time()
x <- st_sftime(a = 3, g, time = time)
st_time(x) 
#> [1] "2024-09-13 09:15:20 UTC"

## assign a vector with time information

# to sf object
x <- st_sf(a = 3, g)
st_time(x) <- time
x
#> Spatiotemporal feature collection with 1 feature and 1 field
#> Geometry type: POINT
#> Dimension:     XY
#> Bounding box:  xmin: 1 ymin: 2 xmax: 1 ymax: 2
#> CRS:           NA
#> Time column with classes: 'POSIXct', 'POSIXt'.
#> Representing 2024-09-13 09:15:20.936623.
#>   a           g                time
#> 1 3 POINT (1 2) 2024-09-13 09:15:20

# to sftime object
x <- st_sftime(a = 3, g, time = time)
st_time(x) <- Sys.time()

## change the time column to another already existing column
st_time(x) <- "a"

## remove time column from sftime object
st_time(x) <- NULL

## pipe-friendly

# assign time column to sf object
x <- st_sf(a = 3, g)
x <- st_set_time(x, time)

# remove time column from sftime object
st_set_time(x, NULL)
#> Simple feature collection with 1 feature and 1 field
#> Geometry type: POINT
#> Dimension:     XY
#> Bounding box:  xmin: 1 ymin: 2 xmax: 1 ymax: 2
#> CRS:           NA
#>   a           g
#> 1 3 POINT (1 2)

## drop time column and class

# same as x <- st_set_time(x, NULL)
st_drop_time(x)
#> Simple feature collection with 1 feature and 1 field
#> Geometry type: POINT
#> Dimension:     XY
#> Bounding box:  xmin: 1 ymin: 2 xmax: 1 ymax: 2
#> CRS:           NA
#>   a           g
#> 1 3 POINT (1 2)