st_transform function

transform geometries in stars objects to a new coordinate reference system, without warping

## S3 method for class 'stars'
st_transform(x, crs, ...)

st_transform_proj.stars(x, crs, ...)

Arguments

• x: object of class stars, with either raster or simple feature geometries
• crs: object of class crs with target crs
• ...: ignored

Details

For simple feature dimensions, st_transform is called, leading to lossless transformation. For gridded spatial data, a curvilinear grid with transformed grid cell (centers) is returned, which is also lossless. To convert this to a regular grid in the new CRS, use st_warp (which is in general lossy).

If array values contain geometries and an array as a whole is of class sfc and has a non-missing CRS, array geometries are also transformed.

Examples

geomatrix = system.file("tif/geomatrix.tif", package = "stars")
(x = read_stars(geomatrix))
new = st_crs('OGC:CRS84')
y = st_transform(x, new)
plot(st_transform(st_as_sfc(st_bbox(x)), new), col = NA, border = 'red')
plot(st_as_sfc(y, as_points=FALSE), col = NA, border = 'green', axes = TRUE, add = TRUE)
image(y, col = heat.colors(12), add = TRUE)
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), add = TRUE)

See Also

st_warp