cdm/src/main/java/ucar/nc2/ft2/simpgeometry/SimpleGeometryReader.java
public Polygon readPolygon(String name, int index) {
		
		Variable polyvar = ds.findVariable(name);
		if(polyvar == null) return null;
		
		Polygon poly = null;
		
		// CFConvention
		if(ds.findGlobalAttribute(CF.CONVENTIONS) != null)
			if(ucar.nc2.dataset.conv.CF1Convention.getVersion(ds.findGlobalAttribute(CF.CONVENTIONS).getStringValue()) >= 8)
				poly = new CFPolygon();
		
		if(poly == null) return null;
		else return poly.setupPolygon(ds, polyvar, index);
	}
public Polygon readPolygon(String name, int index) {
		
		Variable polyvar = ds.findVariable(name);
		if(polyvar == null) return null;
		
		Polygon poly = null;
		
		// CFConvention
		if(ds.findGlobalAttribute(CF.CONVENTIONS) != null)
			if(ucar.nc2.dataset.conv.CF1Convention.getVersion(ds.findGlobalAttribute(CF.CONVENTIONS).getStringValue()) >= 8)
				poly = new CFPolygon();
		
		if(poly == null) return null;
		else return poly.setupPolygon(ds, polyvar, index);
	}
Returns a Polygon given a variable name and the geometric index. If the Polygon is not found it will return null. If the Polygon is a part of the Multi-Polygon, it will return the head
(the first Polygon in the series which constitutes the Multi-Polygon).

@param name of the variable which holds the Polygon
@param index of the Polygon within the variable
@return a new polygon with all associated information