Examples for 'stars::st_warp'

Warp (resample) grids in stars objects to a new grid, possibly in an new coordinate reference system

Aliases: st_warp

Keywords: 

### ** Examples

geomatrix = system.file("tif/geomatrix.tif", package = "stars")
(x = read_stars(geomatrix))

stars object with 2 dimensions and 1 attribute
attribute(s):
               Min. 1st Qu. Median    Mean 3rd Qu. Max.
geomatrix.tif    74     107    123 126.765     132  255
dimension(s):
  from to  offset delta                refsys point x/y
x    1 20 1841002   1.5 WGS 84 / UTM zone 11N  TRUE [x]
y    1 20 1144003  -1.5 WGS 84 / UTM zone 11N  TRUE [y]
sheared raster with parameters: -5 -5 

new_crs = st_crs('OGC:CRS84')
y = st_warp(x, crs = new_crs)
plot(st_transform(st_as_sfc(st_bbox(x)), new_crs), col = NA, border = 'red')
plot(st_as_sfc(y, as_points=FALSE), col = NA, border = 'green', axes = TRUE, add = TRUE)
image(y, add = TRUE, nbreaks = 6)
plot(st_as_sfc(y, as_points=TRUE), pch=3, cex=.5, col = 'blue', add = TRUE)
plot(st_transform(st_as_sfc(x, as_points=FALSE), new_crs), add = TRUE)
plot of chunk example-stars-st_warp-1
# warp 0-360 raster to -180-180 raster:
r = read_stars(system.file("nc/reduced.nc", package = "stars"))

sst, anom, err, ice, 

r %>% st_set_crs('OGC:CRS84') %>% st_warp(st_as_stars(st_bbox(), dx = 2)) -> s
plot(r, axes = TRUE) # no CRS set, so no degree symbols in labels
plot of chunk example-stars-st_warp-1
plot(s, axes = TRUE)
plot of chunk example-stars-st_warp-1
# downsample raster (90 to 270 m)
r = read_stars(system.file("tif/olinda_dem_utm25s.tif", package = "stars"))
r270 = st_as_stars(st_bbox(r), dx = 270)
r270 = st_warp(r, r270)
[Package stars version 0.6-7 Index]