I have some NetCDF files that aren't displaying correcly in ArcMap 10.7 (or when plotted in R...). I found some help fixing the extent here. Here is what I see for the extent:
library(ncdf4) library(raster) library(rgdal) library(gdalUtils) filename <- "./netcdf_test/comp20180702.120000.nc" tpw_raster <- brick(filename, varname="tpwGrid") Result:
> tpw_raster <- brick(filename, varname="tpwGrid") [1] "vobjtovarid4: **** WARNING **** I was asked to get a varid for dimension named lon BUT this dimension HAS NO DIMVAR! Code will probably fail at this point" [1] "vobjtovarid4: **** WARNING **** I was asked to get a varid for dimension named lat BUT this dimension HAS NO DIMVAR! Code will probably fail at this point" tpw_raster; class(tpw_raster) Result:
> tpw_raster; class(tpw_raster) class : RasterBrick dimensions : 721, 1440, 1038240, 1 (nrow, ncol, ncell, nlayers) resolution : 1, 1.998611 (x, y) extent : 0.5, 1440.5, 0.0006944444, 1440.999 (xmin, xmax, ymin, ymax) crs : +proj=longlat +datum=WGS84 +no_defs source : comp20180702.120000.nc names : layer varname : tpwGrid [1] "RasterBrick" attr(,"package") [1] "raster" Here I check the extent info, then fix the extent, and try to write the file:
polnc <- nc_open(filename) #Get extent info ncvar_get(polnc, "lonArr") ncvar_get(polnc, "latArr") extent(tpw_raster) <- c(-180, 179.75, -90, 90) #plot(tpw_raster) writeRaster(tpw_raster, "./netcdf_test/test01.nc", format="CDF", varname="tpw", xname="lon", yname="lat", overwrite=TRUE) #Creates a .nc file, but it is does not open in ArcGIS: "ERROR 000237 One or more dimensions are invald" #writeGDAL(tpw_raster, "./netcdf_test/test01.adf",drivername = "AIG", type = "Float32") #Error in (function (classes, fdef, mtable) : # unable to find an inherited method for function ‘gridded’ for signature ‘"RasterBrick"’ When I use writeRaster a file is produced but I get the stated error when I try to open it in ArcGIS. I first tried writeGDAL because ultimately I want it to be in GRID format but I get an error for that also. Here's what I see when I look at in in R (it seems to plot fine):
filename2 <- "./netcdf_test/test01.nc" tpw_out <- brick(filename2, varname="tpw") tpw_out; class(tpw_out) Result:
> tpw_raster; class(tpw_raster) class : RasterBrick dimensions : 721, 1440, 1038240, 1 (nrow, ncol, ncell, nlayers) resolution : 0.2498264, 0.2496533 (x, y) extent : -180, 179.75, -90, 90 (xmin, xmax, ymin, ymax) crs : +proj=longlat +datum=WGS84 +no_defs source : comp20180702.120000.nc names : layer varname : tpwGrid [1] "RasterBrick" attr(,"package") [1] "raster" > filename2 <- "./netcdf_test/test01.nc" > tpw_out <- brick(filename2, varname="tpw") > tpw_out; class(tpw_out) class : RasterBrick dimensions : 721, 1440, 1038240, 1 (nrow, ncol, ncell, nlayers) resolution : 0.2498264, 0.2496533 (x, y) extent : -180, 179.75, -90, 90 (xmin, xmax, ymin, ymax) crs : +proj=longlat +datum=WGS84 +no_defs source : test01.nc names : X1 min values : 0.0625 max values : 106.9375 z (unknown): 1 varname : tpw [1] "RasterBrick" attr(,"package") [1] "raster" Could ArcMap not liking it have something to do with the "z (unknown)?"
I don't have or need a time dimension or any other z dimension.
res(x) <- c(0.2498264, 0.2498264)res(tpw_raster) <- c(0.2498264, 0.2498264)beforeextent(tpw_raster) <- c(-180, 179.75, -90, 90)and I getWarning message: In .local(x, filename, ...) : all cell values are NA. When I switch the order I getWarning message: In .couldBeLonLat(x, warnings = warnings) : raster has a longitude/latitude CRS, but coordinates do not match that. Either way I still get the same error in ArcGIS.