Calculates the bounding box of coordinates. This does not read the "bbox" attribute, it re-calculates the bounding box from the geometry coordinates
sf_bbox(obj, x = NULL, y = NULL)matrix, data.frame, sfg, sfc or sf object.
x geometry column
y geometry column
## data.frame
df <- data.frame(
id1 = c(1,1,1,1,1,1,1,1,2,2,2,2)
, id2 = c(1,1,1,1,2,2,2,2,1,1,1,1)
, x = c(0,0,1,1,1,1,2,2,3,4,4,3)
, y = c(0,1,1,0,1,2,2,1,3,3,4,4)
)
sf_bbox( obj = df[, c("x","y")] )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
sf_bbox( obj = df, x = "x", y = "y" )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
## sfg objects
pt <- sfg_point(obj = df[1, ], x = "x", y = "y", z = "id1")
mpt <- sfg_multipoint(obj = df, x = "x", y = "y")
ls <- sfg_linestring(obj = df, x = "x", y = "y")
mls <- sfg_multilinestring(obj = df, x = "x", y = "y")
p <- sfg_polygon(obj = df, x = "x" , y = "y")
mp <- sfg_multipolygon(obj = df, x = "x", y = "y", close = FALSE )
sf_bbox( pt )
#> xmin ymin xmax ymax
#> 0 0 0 0
#> attr(,"class")
#> [1] "bbox"
sf_bbox( mpt )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
sf_bbox( ls )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
sf_bbox( mls )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
sf_bbox( p )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
sf_bbox( mp )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
## sfc objects
pt <- sfc_point(obj = df, x = "x", y = "y", z = "id1")
mpt <- sfc_multipoint(obj = df, x = "x", y = "y", multipoint_id = "id1")
ls <- sfc_linestring(obj = df, x = "x", y = "y", linestring_id = "id1")
mls <- sfc_multilinestring(obj = df, x = "x", y = "y", multilinestring_id = "id1")
p <- sfc_polygon(
obj = df
, x = "x"
, y = "y"
, polygon_id = "id1"
, linestring_id = "id2"
, close = FALSE
)
mp <- sfc_multipolygon(
obj = df
, x = "x"
, y = "y"
, multipolygon_id = "id1"
, linestring_id = "id2"
, close = FALSE
)
sf_bbox( pt )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
sf_bbox( mpt )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
sf_bbox( ls )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
sf_bbox( mls )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
sf_bbox( p )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
sf_bbox( mp )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
## sf objects
pt <- sf_point(obj = df, x = "x", y = "y", z = "id1")
mpt <- sf_multipoint(obj = df, x = "x", y = "y", multipoint_id = "id1")
ls <- sf_linestring(obj = df, x = "x", y = "y", linestring_id = "id1")
mls <- sf_multilinestring(obj = df, x = "x", y = "y", multilinestring_id = "id1")
p <- sf_polygon(
obj = df
, x = "x"
, y = "y"
, polygon_id = "id1"
, linestring_id = "id2"
, close = FALSE
)
mp <- sf_multipolygon(
obj = df
, x = "x"
, y = "y"
, multipolygon_id = "id1"
, linestring_id = "id2"
, close = FALSE
)
sf_bbox( pt )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
sf_bbox( mpt )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
sf_bbox( ls )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
sf_bbox( mls )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
sf_bbox( p )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
sf_bbox( mp )
#> xmin ymin xmax ymax
#> 0 0 4 4
#> attr(,"class")
#> [1] "bbox"
## you can use it to update a bounding-box if it gets corrupted
attr( mpt, "bbox" ) <- c(1:5)
mpt ## incorrect values
#> id1 geometry
#> 1 1 0, 0, 1, 1, 1, 1, 2, 2, 0, 1, 1, 0, 1, 2, 2, 1
#> 2 2 3, 4, 4, 3, 3, 3, 4, 4
attr( mpt, "bbox" ) <- sf_bbox( mpt )
mpt ## back to correct values
#> id1 geometry
#> 1 1 0, 0, 1, 1, 1, 1, 2, 2, 0, 1, 1, 0, 1, 2, 2, 1
#> 2 2 3, 4, 4, 3, 3, 3, 4, 4