Spatial joins between sf and stars objects
Thanks Edzer, I should have checked if st_extract kept the order of the rows. In this case, a way to do it more generally is:
sf1 <- bind_cols(st_drop_geometry(sf1),
st_extract(st1, sf1))
Edzer Pebesma writes:
st_join does a spatial join, which comes at a cost; since st_extract doesn't change the row order of the sf object, you could as well use st_extract(st1, sf1) %>% mutate(nums = sf1$nums) On 03/02/2021 17:10, Julian M. Burgos wrote:
Dear list,
What would be the best way to do a spatial join between a sf object (of POINT geometry) and a star object, so the sf object gets the values of the corresponding pixels in the star object? I have done using a combination of st_join and st_extract, but it feels a bit clunky. Is there a better way?
Here is what I have done:
## --------------------------------------------------------------
## Load a stars object
st1 <- read_stars(system.file("tif/L7_ETMs.tif", package = "stars")) %>%
slice(band, 1)
## Create an sf object
set.seed(100)
bb <- st_bbox(st1)
sf1 <- tibble(lon = runif(n = 10, min = bb[1], max = bb[3]),
lat = runif(n = 10, min = bb[2], max = bb[4]),
nums = 1:10) %>%
st_as_sf(coords = c("lon", "lat"), crs = st_crs(st1))
## Do the spatial join
sf1 <- st_extract(st1, sf1) %>%
st_join(sf1)
## --------------------------------------------------------------
Thanks,
Julian
--
Julian Mariano Burgos, PhD
Hafranns?knastofnun, ranns?kna- og r??gjafarstofnun hafs og vatna/
Marine and Freshwater Research Institute
Botnsj?varsvi?s / Demersal Division
Fornub??ir 5, IS-220 Hafnarfj?r?ur, Iceland
http://www.hafogvatn.is/
S?mi/Telephone : +354-5752037
Netfang/Email: julian.burgos at hafogvatn.is
_______________________________________________ R-sig-Geo mailing list R-sig-Geo at r-project.org https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fstat.ethz.ch%2Fmailman%2Flistinfo%2Fr-sig-geo&data=04%7C01%7C%7C38c8e24fcf1d4b6fa70308d8c86923d7%7C8e105b94435e4303a61063620dbe162b%7C0%7C0%7C637479701198004036%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=Z7hRM4MwCwNdegSavTXPJIAlRGJ1DqUNAsm%2Fp9lPgeE%3D&reserved=0
_______________________________________________ R-sig-Geo mailing list R-sig-Geo at r-project.org https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fstat.ethz.ch%2Fmailman%2Flistinfo%2Fr-sig-geo&data=04%7C01%7C%7C38c8e24fcf1d4b6fa70308d8c86923d7%7C8e105b94435e4303a61063620dbe162b%7C0%7C0%7C637479701198004036%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=Z7hRM4MwCwNdegSavTXPJIAlRGJ1DqUNAsm%2Fp9lPgeE%3D&reserved=0
-- Julian Mariano Burgos, PhD Hafranns?knastofnun, ranns?kna- og r??gjafarstofnun hafs og vatna/ Marine and Freshwater Research Institute Botnsj?varsvi?s / Demersal Division Fornub??ir 5, IS-220 Hafnarfj?r?ur, Iceland www.hafogvatn.is S?mi/Telephone : +354-5752037 Netfang/Email: julian.burgos at hafogvatn.is