多边形数据与栅格数据的聚合（带有sf::aggregate()）会生成一系列规则的缺失数据。
请考虑以下代码：
require(sf)
require(stars)
# Download here => http://www.filedropper.com/adaptorcamsregionalfcretrieve-15879390618606012-22402-6-64f0e215-609d-4ca6-b65c-a9ef7dc53370
raster_file <-
"adaptor.cams_regional_fc.retrieve-1587939061.8606012-22402-6-64f0e215-609d-4ca6-b65c-a9ef7dc53370.nc"
# Download here => https://drive.google.com/file/d/1fEhy3V4h1h5efDMrfa0x_mvnx2VL5T66/view?usp=sharing
polygon_file <-
"hex_ita_1km.sf.RData"
r <-
read_stars(raster_file)
load(polygon_file)
st_crs(r) <- 4326
st_crs(hex_ita_1km.sf) <- st_crs(32632)
请注意，r这两个变量中不包含任何缺失数据
summary(r$pm10_conc)
summary(r$pm2p5_conc)
Min. 1st Qu. Median Mean 3rd Qu. Max.0.08376 4.79556 9.77700 14.13988 18.06134 196.88487
Min. 1st Qu. Median Mean 3rd Qu. Max.0.05215 2.08035 4.39209 5.51724 7.46488 54.89545
a <-
aggregate(st_transform(r, 32632),
by = hex_ita_1km.sf,
FUN = mean)
plot(a, border = NA)