R: Examples for 'sf::st_line

### ** Examples

ls = st_sfc(st_linestring(rbind(c(0,0),c(0,1))),
        st_linestring(rbind(c(0,0),c(10,0))))
st_line_sample(ls, density = 1)

Geometry set for 2 features 
Geometry type: MULTIPOINT
Dimension:     XY
Bounding box:  xmin: 0 ymin: 0 xmax: 9.5 ymax: 0.5
CRS:           NA

MULTIPOINT ((0 0.5))

MULTIPOINT ((0.5 0), (1.5 0), (2.5 0), (3.5 0),...

ls = st_sfc(st_linestring(rbind(c(0,0),c(0,1))),
 st_linestring(rbind(c(0,0),c(.1,0))), crs = 4326)
try(st_line_sample(ls, density = 1/1000)) # error

Error in st_line_sample(ls, density = 1/1000) : 
  st_line_sample for longitude/latitude not supported; use st_segmentize?

st_line_sample(st_transform(ls, 3857), n = 5) # five points for each line

Geometry set for 2 features 
Geometry type: MULTIPOINT
Dimension:     XY
Bounding box:  xmin: 0 ymin: 0 xmax: 10018.75 ymax: 100192.6
Projected CRS: WGS 84 / Pseudo-Mercator

MULTIPOINT ((0 11132.51), (0 33397.54), (0 5566...

MULTIPOINT ((1113.195 0), (3339.585 0), (5565.9...

st_line_sample(st_transform(ls, 3857), n = c(1, 3)) # one and three points

Geometry set for 2 features 
Geometry type: MULTIPOINT
Dimension:     XY
Bounding box:  xmin: 0 ymin: 0 xmax: 9276.624 ymax: 55662.57
Projected CRS: WGS 84 / Pseudo-Mercator

MULTIPOINT ((0 55662.57))

MULTIPOINT ((1855.325 0), (5565.975 0), (9276.6...

st_line_sample(st_transform(ls, 3857), density = 1/1000) # one per km

Geometry set for 2 features 
Geometry type: MULTIPOINT
Dimension:     XY
Bounding box:  xmin: 0 ymin: 0 xmax: 10625.95 ymax: 110823.7
Projected CRS: WGS 84 / Pseudo-Mercator

MULTIPOINT ((0 501.4646), (0 1504.394), (0 2507...

MULTIPOINT ((505.9977 0), (1517.993 0), (2529.9...

st_line_sample(st_transform(ls, 3857), density = c(1/1000, 1/10000)) # one per km, one per 10 km

Geometry set for 2 features 
Geometry type: MULTIPOINT
Dimension:     XY
Bounding box:  xmin: 0 ymin: 0 xmax: 5565.975 ymax: 110823.7
Projected CRS: WGS 84 / Pseudo-Mercator

MULTIPOINT ((0 501.4646), (0 1504.394), (0 2507...

MULTIPOINT ((5565.975 0))

st_line_sample(st_transform(ls, 3857), density = units::set_units(1, 1/km)) # one per km

Geometry set for 2 features 
Geometry type: MULTIPOINT
Dimension:     XY
Bounding box:  xmin: 0 ymin: 0 xmax: 10625.95 ymax: 110823.7
Projected CRS: WGS 84 / Pseudo-Mercator

MULTIPOINT ((0 501.4646), (0 1504.394), (0 2507...

MULTIPOINT ((505.9977 0), (1517.993 0), (2529.9...

# five equidistant points including start and end:
st_line_sample(st_transform(ls, 3857), sample = c(0, 0.25, 0.5, 0.75, 1))

Geometry set for 2 features 
Geometry type: MULTIPOINT
Dimension:     XY
Bounding box:  xmin: 0 ymin: 0 xmax: 11131.95 ymax: 111325.1
Projected CRS: WGS 84 / Pseudo-Mercator

MULTIPOINT ((0 0), (0 27831.29), (0 55662.57), ...

MULTIPOINT ((0 0), (2782.987 0), (5565.975 0), ...

Examples for 'sf::st_line_sample'

Sample points on a linear geometry