Barebones tool to subset a netCDF grid dataset based on geographic (WGS84) bounding box

gistfile1.java

/**

Barebones tool to subset a netCDF grid dataset based on geographic bounding box.
Requires NetCDF-Java version 4.3 (may work with 4.5, haven't tested it):
@see http://www.unidata.ucar.edu/software/thredds/current/netcdf-java/documentation.htm

@author [email protected]

To use:

export CLASSPATH=${CLASSPATH}:./lib/netcdfAll-4.3.jar
javac SpatialSubset.java
java SpatialSubset mynetCDF.nc -78.931940 36.013984 -78.921160 36.023954 mynetCDF_spsubset.nc

*/

import ucar.nc2.dt.grid.GridDataset;
import ucar.nc2.dt.GridDatatype;
import ucar.nc2.dt.grid.NetcdfCFWriter;
import ucar.ma2.InvalidRangeException;
import ucar.unidata.geoloc.LatLonRect;
import ucar.unidata.geoloc.LatLonPoint;
import ucar.unidata.geoloc.LatLonPointImpl;

public class SpatialSubset {

	public static void main(String[] args) throws java.io.IOException, InvalidRangeException {
	
		GridDataset gridDs = GridDataset.open(args[0]);
		// Grid list
		java.util.List<GridDatatype> grids = gridDs.getGrids();
		java.util.List<java.lang.String> gridList = new java.util.ArrayList<java.lang.String>();
		for (GridDatatype grid : grids) {
			gridList.add(grid.getName());
		}
		
		// Bounding box
		double xmin = Double.parseDouble(args[1]);
		double ymin = Double.parseDouble(args[2]);
		double xmax = Double.parseDouble(args[3]);
		double ymax = Double.parseDouble(args[4]);
		
		LatLonPoint rectLeft = new LatLonPointImpl(ymin, xmin);
		LatLonPoint rectRight = new LatLonPointImpl(ymax, xmax);
		LatLonRect rect = new LatLonRect(rectLeft, rectRight);
		
		// Output file name
		String outfile = args[5];
		
		NetcdfCFWriter.makeFile(outfile, gridDs, gridList, rect, null);
	
	}

}