I am attempting to overlay a netcdf4 raster containing Aerosol Height data over Hawaii specifically. A sample file is available here. My variables of interest are latitude, longitude, time and aerosol height. Here is some reproducible data.
s1 <- data.frame(as.vector(lon), as.vector(lat), as.vector(ah))
s1
# as.vector.lon. as.vector.lat. as.vector.ah.
#1 -127.45199 -79.15431 NA
#2 -126.99632 -79.16919 NA
#3 -126.54577 -79.18321 NA
#4 -126.10027 -79.19641 NA
#5 -125.65974 -79.20880 NA
#6 -125.22412 -79.22042 NA
#7 -124.79333 -79.23129 NA
crsLatLon <- "+proj=longlat +datum=WGS84"
ex <- extent(c(-180,180,-90,90))
#empty raster with 0.1 degree resolution
pmraster <- raster(ncol=360*10, nrow=180*10, crs=crsLatLon,ext=ex)
#fills the empty raster with values from dataframe, s1
pmraster <- rasterize(s1[,1:2], pmraster, s1[,3], fun=mean, na.rm=T)
show(pmraster)
#class : RasterLayer
#dimensions : 1800, 3600, 6480000 (nrow, ncol, ncell)
#resolution : 0.1, 0.1 (x, y)
#extent : -180, 180, -90, 90 (xmin, xmax, ymin, ymax)
#crs : +proj=longlat +datum=WGS84 +ellps=WGS84 +towgs84=0,0,0
#source : r_tmp_2020-06-26_114048_16840_75885.grd
#names : layer
#values : 0.1314196, 9424.118 (min, max)
#specifies region over Hawaii
exHI <- extent(c(-180,-140,10,30))
levelplot(crop(pmraster,exHI))
#Error: $ operator is invalid for atomic vectors
#In addition: Warning messages:
#1: In min(x) : no non-missing arguments to min; returning Inf
#2: In max(x) : no non-missing arguments to max; returning -Inf
#3: In min(x) : no non-missing arguments to min; returning Inf
#4: In max(x) : no non-missing arguments to max; returning -Inf
Can anyone help explain why I am getting this error message and how I may proceed to produce the desired raster image? Thank you in advance!
After trying this on different files, it became clear to me that there was no data available over the specific region I was isolating, resulting in my confusion.