DOI-USGS/ncdfgeom

Update NetCDF Simple Geometry Convention to match final spec.

Closed this issue · 5 comments

dblodgett-usgs commented

See final form here: cf-convention/cf-conventions#115 will require a bit of double checking and review.

dblodgett-usgs commented

Examples - Contiguous Ragged Arrays

Created 2018-05-03 08:36:42

Point (2D)

Well Known Text (WKT): POINT (30 10)
Common Data Language (CDL):

netcdf sample_point {
dimensions:
	instance = 1 ;
variables:
	double x(instance) ;
		x:units = "degrees_east" ;
		x:standard_name = "longitude" ;
		x:cf_role = "geometry_x_node" ;
	double y(instance) ;
		y:units = "degrees_north" ;
		y:standard_name = "latitude" ;
		y:cf_role = "geometry_y_node" ;
	float geometry_container ;
		geometry_container:geometry_type = "point" ;
		geometry_container:node_coordinates = "x y" ;
		geometry_container:grid_mapping = "grid_mapping" ;
	float grid_mapping ;
		grid_mapping:grid_mapping_name = "latitude_longitude" ;
		grid_mapping:semi_major_axis = 6378137. ;
		grid_mapping:inverse_flattening = 298.257223563 ;
		grid_mapping:longitude_of_prime_meridian = 0. ;

// global attributes:
		:Conventions = "CF-1.8" ;
data:

 x = 30 ;

 y = 10 ;

 geometry_container = _ ;

 grid_mapping = _ ;
}

LineString (2D)

Well Known Text (WKT): LINESTRING (30 10, 10 30, 40 40)
Common Data Language (CDL):

netcdf sample_linestring {
dimensions:
	node = 3 ;
	instance = 1 ;
variables:
	double x(node) ;
		x:units = "degrees_east" ;
		x:standard_name = "longitude" ;
		x:cf_role = "geometry_x_node" ;
	double y(node) ;
		y:units = "degrees_north" ;
		y:standard_name = "latitude" ;
		y:cf_role = "geometry_y_node" ;
	float geometry_container ;
		geometry_container:geometry_type = "line" ;
		geometry_container:node_count = "node_count" ;
		geometry_container:node_coordinates = "x y" ;
		geometry_container:grid_mapping = "grid_mapping" ;
	int node_count(instance) ;
		node_count:long_name = "count of coordinates in each instance geometry" ;
	float grid_mapping ;
		grid_mapping:grid_mapping_name = "latitude_longitude" ;
		grid_mapping:semi_major_axis = 6378137. ;
		grid_mapping:inverse_flattening = 298.257223563 ;
		grid_mapping:longitude_of_prime_meridian = 0. ;

// global attributes:
		:Conventions = "CF-1.8" ;
data:

 x = 30, 10, 40 ;

 y = 10, 30, 40 ;

 geometry_container = _ ;

 node_count = 3 ;

 grid_mapping = _ ;
}

Polygon (2D)

Well Known Text (WKT): POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))
Common Data Language (CDL):

netcdf sample_polygon {
dimensions:
	node = 5 ;
	instance = 1 ;
variables:
	double x(node) ;
		x:units = "degrees_east" ;
		x:standard_name = "longitude" ;
		x:cf_role = "geometry_x_node" ;
	double y(node) ;
		y:units = "degrees_north" ;
		y:standard_name = "latitude" ;
		y:cf_role = "geometry_y_node" ;
	float geometry_container ;
		geometry_container:geometry_type = "polygon" ;
		geometry_container:node_count = "node_count" ;
		geometry_container:node_coordinates = "x y" ;
		geometry_container:grid_mapping = "grid_mapping" ;
	int node_count(instance) ;
		node_count:long_name = "count of coordinates in each instance geometry" ;
	float grid_mapping ;
		grid_mapping:grid_mapping_name = "latitude_longitude" ;
		grid_mapping:semi_major_axis = 6378137. ;
		grid_mapping:inverse_flattening = 298.257223563 ;
		grid_mapping:longitude_of_prime_meridian = 0. ;

// global attributes:
		:Conventions = "CF-1.8" ;
data:

 x = 30, 40, 20, 10, 30 ;

 y = 10, 40, 40, 20, 10 ;

 geometry_container = _ ;

 node_count = 5 ;

 grid_mapping = _ ;
}

MultiPoint (2D)

Well Known Text (WKT): MULTIPOINT ((10 40), (40 30), (20 20), (30 10))
Common Data Language (CDL):

netcdf sample_multipoint {
dimensions:
	node = 4 ;
	instance = 1 ;
variables:
	double x(node) ;
		x:units = "degrees_east" ;
		x:standard_name = "longitude" ;
		x:cf_role = "geometry_x_node" ;
	double y(node) ;
		y:units = "degrees_north" ;
		y:standard_name = "latitude" ;
		y:cf_role = "geometry_y_node" ;
	float geometry_container ;
		geometry_container:geometry_type = "multipoint" ;
		geometry_container:node_count = "node_count" ;
		geometry_container:node_coordinates = "x y" ;
		geometry_container:grid_mapping = "grid_mapping" ;
	int node_count(instance) ;
		node_count:long_name = "count of coordinates in each instance geometry" ;
	float grid_mapping ;
		grid_mapping:grid_mapping_name = "latitude_longitude" ;
		grid_mapping:semi_major_axis = 6378137. ;
		grid_mapping:inverse_flattening = 298.257223563 ;
		grid_mapping:longitude_of_prime_meridian = 0. ;

// global attributes:
		:Conventions = "CF-1.8" ;
data:

 x = 10, 40, 20, 30 ;

 y = 40, 30, 20, 10 ;

 geometry_container = _ ;

 node_count = 4 ;

 grid_mapping = _ ;
}

MultiLineString (2D)

Well Known Text (WKT): MULTILINESTRING ((10 10, 20 20, 10 40), (40 40, 30 30, 40 20, 30 10))
Common Data Language (CDL):

netcdf sample_multilinestring {
dimensions:
	node = 7 ;
	instance = 1 ;
	part = 2 ;
variables:
	double x(node) ;
		x:units = "degrees_east" ;
		x:standard_name = "longitude" ;
		x:cf_role = "geometry_x_node" ;
	double y(node) ;
		y:units = "degrees_north" ;
		y:standard_name = "latitude" ;
		y:cf_role = "geometry_y_node" ;
	float geometry_container ;
		geometry_container:geometry_type = "multiline" ;
		geometry_container:node_count = "node_count" ;
		geometry_container:node_coordinates = "x y" ;
		geometry_container:grid_mapping = "grid_mapping" ;
		geometry_container:part_node_count = "part_node_count" ;
	int node_count(instance) ;
		node_count:long_name = "count of coordinates in each instance geometry" ;
	float grid_mapping ;
		grid_mapping:grid_mapping_name = "latitude_longitude" ;
		grid_mapping:semi_major_axis = 6378137. ;
		grid_mapping:inverse_flattening = 298.257223563 ;
		grid_mapping:longitude_of_prime_meridian = 0. ;
	int part_node_count(part) ;
		part_node_count:long_name = "count of nodes in each geometry part" ;

// global attributes:
		:Conventions = "CF-1.8" ;
data:

 x = 10, 20, 10, 40, 30, 40, 30 ;

 y = 10, 20, 40, 40, 30, 20, 10 ;

 geometry_container = _ ;

 node_count = 7 ;

 grid_mapping = _ ;

 part_node_count = 3, 4 ;
}

MultiPolygon (2D)

Well Known Text (WKT): MULTIPOLYGON (((30 20, 45 40, 10 40, 30 20)), ((15 5, 40 10, 10 20, 5 10, 15 5)))
Common Data Language (CDL):

netcdf sample_multipolygon {
dimensions:
	node = 9 ;
	instance = 1 ;
	part = 2 ;
variables:
	double x(node) ;
		x:units = "degrees_east" ;
		x:standard_name = "longitude" ;
		x:cf_role = "geometry_x_node" ;
	double y(node) ;
		y:units = "degrees_north" ;
		y:standard_name = "latitude" ;
		y:cf_role = "geometry_y_node" ;
	float geometry_container ;
		geometry_container:geometry_type = "multipolygon" ;
		geometry_container:node_count = "node_count" ;
		geometry_container:node_coordinates = "x y" ;
		geometry_container:grid_mapping = "grid_mapping" ;
		geometry_container:part_node_count = "part_node_count" ;
	int node_count(instance) ;
		node_count:long_name = "count of coordinates in each instance geometry" ;
	float grid_mapping ;
		grid_mapping:grid_mapping_name = "latitude_longitude" ;
		grid_mapping:semi_major_axis = 6378137. ;
		grid_mapping:inverse_flattening = 298.257223563 ;
		grid_mapping:longitude_of_prime_meridian = 0. ;
	int part_node_count(part) ;
		part_node_count:long_name = "count of nodes in each geometry part" ;

// global attributes:
		:Conventions = "CF-1.8" ;
data:

 x = 30, 45, 10, 30, 15, 40, 10, 5, 15 ;

 y = 20, 40, 40, 20, 5, 10, 20, 10, 5 ;

 geometry_container = _ ;

 node_count = 9 ;

 grid_mapping = _ ;

 part_node_count = 4, 5 ;
}

Polygon with One Interior Ring (2D)

Well Known Text (WKT): POLYGON ((35 10, 45 45, 15 40, 10 20, 35 10), (20 30, 35 35, 30 20, 20 30))
Common Data Language (CDL):

netcdf sample_polygon_hole {
dimensions:
	node = 9 ;
	instance = 1 ;
	part = 2 ;
variables:
	double x(node) ;
		x:units = "degrees_east" ;
		x:standard_name = "longitude" ;
		x:cf_role = "geometry_x_node" ;
	double y(node) ;
		y:units = "degrees_north" ;
		y:standard_name = "latitude" ;
		y:cf_role = "geometry_y_node" ;
	float geometry_container ;
		geometry_container:geometry_type = "polygon" ;
		geometry_container:node_count = "node_count" ;
		geometry_container:node_coordinates = "x y" ;
		geometry_container:grid_mapping = "grid_mapping" ;
		geometry_container:part_node_count = "part_node_count" ;
		geometry_container:interior_ring = "interior_ring" ;
	int node_count(instance) ;
		node_count:long_name = "count of coordinates in each instance geometry" ;
	float grid_mapping ;
		grid_mapping:grid_mapping_name = "latitude_longitude" ;
		grid_mapping:semi_major_axis = 6378137. ;
		grid_mapping:inverse_flattening = 298.257223563 ;
		grid_mapping:longitude_of_prime_meridian = 0. ;
	int part_node_count(part) ;
		part_node_count:long_name = "count of nodes in each geometry part" ;
	int interior_ring(part) ;
		interior_ring:long_name = "type of each geometry part" ;

// global attributes:
		:Conventions = "CF-1.8" ;
data:

 x = 35, 45, 15, 10, 35, 20, 35, 30, 20 ;

 y = 10, 45, 40, 20, 10, 30, 35, 20, 30 ;

 geometry_container = _ ;

 node_count = 9 ;

 grid_mapping = _ ;

 part_node_count = 5, 4 ;

 interior_ring = 0, 1 ;
}

MultiPolygon with One Interior Ring (2D)

Well Known Text (WKT): MULTIPOLYGON (((40 40, 20 45, 45 30, 40 40)), ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35), (30 20, 20 15, 20 25, 30 20)))
Common Data Language (CDL):

netcdf sample_multipolygon_hole {
dimensions:
	node = 14 ;
	instance = 1 ;
	part = 3 ;
variables:
	double x(node) ;
		x:units = "degrees_east" ;
		x:standard_name = "longitude" ;
		x:cf_role = "geometry_x_node" ;
	double y(node) ;
		y:units = "degrees_north" ;
		y:standard_name = "latitude" ;
		y:cf_role = "geometry_y_node" ;
	float geometry_container ;
		geometry_container:geometry_type = "multipolygon" ;
		geometry_container:node_count = "node_count" ;
		geometry_container:node_coordinates = "x y" ;
		geometry_container:grid_mapping = "grid_mapping" ;
		geometry_container:part_node_count = "part_node_count" ;
		geometry_container:interior_ring = "interior_ring" ;
	int node_count(instance) ;
		node_count:long_name = "count of coordinates in each instance geometry" ;
	float grid_mapping ;
		grid_mapping:grid_mapping_name = "latitude_longitude" ;
		grid_mapping:semi_major_axis = 6378137. ;
		grid_mapping:inverse_flattening = 298.257223563 ;
		grid_mapping:longitude_of_prime_meridian = 0. ;
	int part_node_count(part) ;
		part_node_count:long_name = "count of nodes in each geometry part" ;
	int interior_ring(part) ;
		interior_ring:long_name = "type of each geometry part" ;

// global attributes:
		:Conventions = "CF-1.8" ;
data:

 x = 40, 20, 45, 40, 20, 10, 10, 30, 45, 20, 30, 20, 20, 30 ;

 y = 40, 45, 30, 40, 35, 30, 10, 5, 20, 35, 20, 15, 25, 20 ;

 geometry_container = _ ;

 node_count = 14 ;

 grid_mapping = _ ;

 part_node_count = 4, 6, 4 ;

 interior_ring = 0, 0, 1 ;
}

Multiple MultiPolygons with Interior Rings (2D)

Well Known Text (WKT): MULTIPOLYGON(((0 0, 20 0, 20 20, 0 20, 0 0), (1 1, 10 5, 19 1, 1 1), (5 15, 7 19, 9 15, 5 15), (11 15, 13 19, 15 15, 11 15)), ((5 25, 9 25, 7 29, 5 25)), ((11 25, 15 25, 13 29, 11 25)))
Common Data Language (CDL):

netcdf sample_multipolygons_holes {
dimensions:
	node = 25 ;
	instance = 1 ;
	part = 6 ;
variables:
	double x(node) ;
		x:units = "degrees_east" ;
		x:standard_name = "longitude" ;
		x:cf_role = "geometry_x_node" ;
	double y(node) ;
		y:units = "degrees_north" ;
		y:standard_name = "latitude" ;
		y:cf_role = "geometry_y_node" ;
	float geometry_container ;
		geometry_container:geometry_type = "multipolygon" ;
		geometry_container:node_count = "node_count" ;
		geometry_container:node_coordinates = "x y" ;
		geometry_container:grid_mapping = "grid_mapping" ;
		geometry_container:part_node_count = "part_node_count" ;
		geometry_container:interior_ring = "interior_ring" ;
	int node_count(instance) ;
		node_count:long_name = "count of coordinates in each instance geometry" ;
	float grid_mapping ;
		grid_mapping:grid_mapping_name = "latitude_longitude" ;
		grid_mapping:semi_major_axis = 6378137. ;
		grid_mapping:inverse_flattening = 298.257223563 ;
		grid_mapping:longitude_of_prime_meridian = 0. ;
	int part_node_count(part) ;
		part_node_count:long_name = "count of nodes in each geometry part" ;
	int interior_ring(part) ;
		interior_ring:long_name = "type of each geometry part" ;

// global attributes:
		:Conventions = "CF-1.8" ;
data:

 x = 0, 20, 20, 0, 0, 1, 10, 19, 1, 5, 7, 9, 5, 11, 13, 15, 11, 5, 9, 7, 5, 
    11, 15, 13, 11 ;

 y = 0, 0, 20, 20, 0, 1, 5, 1, 1, 15, 19, 15, 15, 15, 19, 15, 15, 25, 25, 29, 
    25, 25, 25, 29, 25 ;

 geometry_container = _ ;

 node_count = 25 ;

 grid_mapping = _ ;

 part_node_count = 5, 4, 4, 4, 4, 4 ;

 interior_ring = 0, 1, 1, 1, 0, 0 ;
}
dblodgett-usgs commented

@twhiteaker you've worked with this stuff more recently than I. Does anything pop out at you on this? Do you have an equivalent example that the python implementation writes out?

twhiteaker commented

Equivalent example:
https://github.com/twhiteaker/netCDF-CF-simple-geometry/wiki/Examples:-Contiguous-Ragged-Arrays

My examples don't have a crs, but otherwise they are representing the same geometries. The things that I see that need updating are:

  • For geometry_type, "multi" should not appear in any values.
  • Instead of cf_role on the node variables, use axis.
dblodgett-usgs commented

Better?

Examples - Contiguous Ragged Arrays

Created 2018-05-03 21:02:37

Point (2D)

Well Known Text (WKT): POINT (30 10)
Common Data Language (CDL):

netcdf sample_point {
dimensions:
	instance = 1 ;
variables:
	double x(instance) ;
		x:units = "degrees_east" ;
		x:standard_name = "longitude" ;
		x:axis = "X" ;
	double y(instance) ;
		y:units = "degrees_north" ;
		y:standard_name = "latitude" ;
		y:axis = "Y" ;
	float geometry_container ;
		geometry_container:geometry_type = "point" ;
		geometry_container:node_coordinates = "x y" ;
		geometry_container:grid_mapping = "grid_mapping" ;
	float grid_mapping ;
		grid_mapping:grid_mapping_name = "latitude_longitude" ;
		grid_mapping:semi_major_axis = 6378137. ;
		grid_mapping:inverse_flattening = 298.257223563 ;
		grid_mapping:longitude_of_prime_meridian = 0. ;

// global attributes:
		:Conventions = "CF-1.8" ;
data:

 x = 30 ;

 y = 10 ;

 geometry_container = _ ;

 grid_mapping = _ ;
}

LineString (2D)

Well Known Text (WKT): LINESTRING (30 10, 10 30, 40 40)
Common Data Language (CDL):

netcdf sample_linestring {
dimensions:
	node = 3 ;
	instance = 1 ;
variables:
	double x(node) ;
		x:units = "degrees_east" ;
		x:standard_name = "longitude" ;
		x:axis = "X" ;
	double y(node) ;
		y:units = "degrees_north" ;
		y:standard_name = "latitude" ;
		y:axis = "Y" ;
	float geometry_container ;
		geometry_container:geometry_type = "line" ;
		geometry_container:node_count = "node_count" ;
		geometry_container:node_coordinates = "x y" ;
		geometry_container:grid_mapping = "grid_mapping" ;
	int node_count(instance) ;
		node_count:long_name = "count of coordinates in each instance geometry" ;
	float grid_mapping ;
		grid_mapping:grid_mapping_name = "latitude_longitude" ;
		grid_mapping:semi_major_axis = 6378137. ;
		grid_mapping:inverse_flattening = 298.257223563 ;
		grid_mapping:longitude_of_prime_meridian = 0. ;

// global attributes:
		:Conventions = "CF-1.8" ;
data:

 x = 30, 10, 40 ;

 y = 10, 30, 40 ;

 geometry_container = _ ;

 node_count = 3 ;

 grid_mapping = _ ;
}

Polygon (2D)

Well Known Text (WKT): POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))
Common Data Language (CDL):

netcdf sample_polygon {
dimensions:
	node = 5 ;
	instance = 1 ;
variables:
	double x(node) ;
		x:units = "degrees_east" ;
		x:standard_name = "longitude" ;
		x:axis = "X" ;
	double y(node) ;
		y:units = "degrees_north" ;
		y:standard_name = "latitude" ;
		y:axis = "Y" ;
	float geometry_container ;
		geometry_container:geometry_type = "polygon" ;
		geometry_container:node_count = "node_count" ;
		geometry_container:node_coordinates = "x y" ;
		geometry_container:grid_mapping = "grid_mapping" ;
	int node_count(instance) ;
		node_count:long_name = "count of coordinates in each instance geometry" ;
	float grid_mapping ;
		grid_mapping:grid_mapping_name = "latitude_longitude" ;
		grid_mapping:semi_major_axis = 6378137. ;
		grid_mapping:inverse_flattening = 298.257223563 ;
		grid_mapping:longitude_of_prime_meridian = 0. ;

// global attributes:
		:Conventions = "CF-1.8" ;
data:

 x = 30, 40, 20, 10, 30 ;

 y = 10, 40, 40, 20, 10 ;

 geometry_container = _ ;

 node_count = 5 ;

 grid_mapping = _ ;
}

MultiPoint (2D)

Well Known Text (WKT): MULTIPOINT ((10 40), (40 30), (20 20), (30 10))
Common Data Language (CDL):

netcdf sample_multipoint {
dimensions:
	node = 4 ;
	instance = 1 ;
variables:
	double x(node) ;
		x:units = "degrees_east" ;
		x:standard_name = "longitude" ;
		x:axis = "X" ;
	double y(node) ;
		y:units = "degrees_north" ;
		y:standard_name = "latitude" ;
		y:axis = "Y" ;
	float geometry_container ;
		geometry_container:geometry_type = "point" ;
		geometry_container:node_count = "node_count" ;
		geometry_container:node_coordinates = "x y" ;
		geometry_container:grid_mapping = "grid_mapping" ;
	int node_count(instance) ;
		node_count:long_name = "count of coordinates in each instance geometry" ;
	float grid_mapping ;
		grid_mapping:grid_mapping_name = "latitude_longitude" ;
		grid_mapping:semi_major_axis = 6378137. ;
		grid_mapping:inverse_flattening = 298.257223563 ;
		grid_mapping:longitude_of_prime_meridian = 0. ;

// global attributes:
		:Conventions = "CF-1.8" ;
data:

 x = 10, 40, 20, 30 ;

 y = 40, 30, 20, 10 ;

 geometry_container = _ ;

 node_count = 4 ;

 grid_mapping = _ ;
}

MultiLineString (2D)

Well Known Text (WKT): MULTILINESTRING ((10 10, 20 20, 10 40), (40 40, 30 30, 40 20, 30 10))
Common Data Language (CDL):

netcdf sample_multilinestring {
dimensions:
	node = 7 ;
	instance = 1 ;
	part = 2 ;
variables:
	double x(node) ;
		x:units = "degrees_east" ;
		x:standard_name = "longitude" ;
		x:axis = "X" ;
	double y(node) ;
		y:units = "degrees_north" ;
		y:standard_name = "latitude" ;
		y:axis = "Y" ;
	float geometry_container ;
		geometry_container:geometry_type = "line" ;
		geometry_container:node_count = "node_count" ;
		geometry_container:node_coordinates = "x y" ;
		geometry_container:grid_mapping = "grid_mapping" ;
		geometry_container:part_node_count = "part_node_count" ;
	int node_count(instance) ;
		node_count:long_name = "count of coordinates in each instance geometry" ;
	float grid_mapping ;
		grid_mapping:grid_mapping_name = "latitude_longitude" ;
		grid_mapping:semi_major_axis = 6378137. ;
		grid_mapping:inverse_flattening = 298.257223563 ;
		grid_mapping:longitude_of_prime_meridian = 0. ;
	int part_node_count(part) ;
		part_node_count:long_name = "count of nodes in each geometry part" ;

// global attributes:
		:Conventions = "CF-1.8" ;
data:

 x = 10, 20, 10, 40, 30, 40, 30 ;

 y = 10, 20, 40, 40, 30, 20, 10 ;

 geometry_container = _ ;

 node_count = 7 ;

 grid_mapping = _ ;

 part_node_count = 3, 4 ;
}

MultiPolygon (2D)

Well Known Text (WKT): MULTIPOLYGON (((30 20, 45 40, 10 40, 30 20)), ((15 5, 40 10, 10 20, 5 10, 15 5)))
Common Data Language (CDL):

netcdf sample_multipolygon {
dimensions:
	node = 9 ;
	instance = 1 ;
	part = 2 ;
variables:
	double x(node) ;
		x:units = "degrees_east" ;
		x:standard_name = "longitude" ;
		x:axis = "X" ;
	double y(node) ;
		y:units = "degrees_north" ;
		y:standard_name = "latitude" ;
		y:axis = "Y" ;
	float geometry_container ;
		geometry_container:geometry_type = "polygon" ;
		geometry_container:node_count = "node_count" ;
		geometry_container:node_coordinates = "x y" ;
		geometry_container:grid_mapping = "grid_mapping" ;
		geometry_container:part_node_count = "part_node_count" ;
	int node_count(instance) ;
		node_count:long_name = "count of coordinates in each instance geometry" ;
	float grid_mapping ;
		grid_mapping:grid_mapping_name = "latitude_longitude" ;
		grid_mapping:semi_major_axis = 6378137. ;
		grid_mapping:inverse_flattening = 298.257223563 ;
		grid_mapping:longitude_of_prime_meridian = 0. ;
	int part_node_count(part) ;
		part_node_count:long_name = "count of nodes in each geometry part" ;

// global attributes:
		:Conventions = "CF-1.8" ;
data:

 x = 30, 45, 10, 30, 15, 40, 10, 5, 15 ;

 y = 20, 40, 40, 20, 5, 10, 20, 10, 5 ;

 geometry_container = _ ;

 node_count = 9 ;

 grid_mapping = _ ;

 part_node_count = 4, 5 ;
}

Polygon with One Interior Ring (2D)

Well Known Text (WKT): POLYGON ((35 10, 45 45, 15 40, 10 20, 35 10), (20 30, 35 35, 30 20, 20 30))
Common Data Language (CDL):

netcdf sample_polygon_hole {
dimensions:
	node = 9 ;
	instance = 1 ;
	part = 2 ;
variables:
	double x(node) ;
		x:units = "degrees_east" ;
		x:standard_name = "longitude" ;
		x:axis = "X" ;
	double y(node) ;
		y:units = "degrees_north" ;
		y:standard_name = "latitude" ;
		y:axis = "Y" ;
	float geometry_container ;
		geometry_container:geometry_type = "polygon" ;
		geometry_container:node_count = "node_count" ;
		geometry_container:node_coordinates = "x y" ;
		geometry_container:grid_mapping = "grid_mapping" ;
		geometry_container:part_node_count = "part_node_count" ;
		geometry_container:interior_ring = "interior_ring" ;
	int node_count(instance) ;
		node_count:long_name = "count of coordinates in each instance geometry" ;
	float grid_mapping ;
		grid_mapping:grid_mapping_name = "latitude_longitude" ;
		grid_mapping:semi_major_axis = 6378137. ;
		grid_mapping:inverse_flattening = 298.257223563 ;
		grid_mapping:longitude_of_prime_meridian = 0. ;
	int part_node_count(part) ;
		part_node_count:long_name = "count of nodes in each geometry part" ;
	int interior_ring(part) ;
		interior_ring:long_name = "type of each geometry part" ;

// global attributes:
		:Conventions = "CF-1.8" ;
data:

 x = 35, 45, 15, 10, 35, 20, 35, 30, 20 ;

 y = 10, 45, 40, 20, 10, 30, 35, 20, 30 ;

 geometry_container = _ ;

 node_count = 9 ;

 grid_mapping = _ ;

 part_node_count = 5, 4 ;

 interior_ring = 0, 1 ;
}

MultiPolygon with One Interior Ring (2D)

Well Known Text (WKT): MULTIPOLYGON (((40 40, 20 45, 45 30, 40 40)), ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35), (30 20, 20 15, 20 25, 30 20)))
Common Data Language (CDL):

netcdf sample_multipolygon_hole {
dimensions:
	node = 14 ;
	instance = 1 ;
	part = 3 ;
variables:
	double x(node) ;
		x:units = "degrees_east" ;
		x:standard_name = "longitude" ;
		x:axis = "X" ;
	double y(node) ;
		y:units = "degrees_north" ;
		y:standard_name = "latitude" ;
		y:axis = "Y" ;
	float geometry_container ;
		geometry_container:geometry_type = "polygon" ;
		geometry_container:node_count = "node_count" ;
		geometry_container:node_coordinates = "x y" ;
		geometry_container:grid_mapping = "grid_mapping" ;
		geometry_container:part_node_count = "part_node_count" ;
		geometry_container:interior_ring = "interior_ring" ;
	int node_count(instance) ;
		node_count:long_name = "count of coordinates in each instance geometry" ;
	float grid_mapping ;
		grid_mapping:grid_mapping_name = "latitude_longitude" ;
		grid_mapping:semi_major_axis = 6378137. ;
		grid_mapping:inverse_flattening = 298.257223563 ;
		grid_mapping:longitude_of_prime_meridian = 0. ;
	int part_node_count(part) ;
		part_node_count:long_name = "count of nodes in each geometry part" ;
	int interior_ring(part) ;
		interior_ring:long_name = "type of each geometry part" ;

// global attributes:
		:Conventions = "CF-1.8" ;
data:

 x = 40, 20, 45, 40, 20, 10, 10, 30, 45, 20, 30, 20, 20, 30 ;

 y = 40, 45, 30, 40, 35, 30, 10, 5, 20, 35, 20, 15, 25, 20 ;

 geometry_container = _ ;

 node_count = 14 ;

 grid_mapping = _ ;

 part_node_count = 4, 6, 4 ;

 interior_ring = 0, 0, 1 ;
}

Multiple MultiPolygons with Interior Rings (2D)

Well Known Text (WKT): MULTIPOLYGON(((0 0, 20 0, 20 20, 0 20, 0 0), (1 1, 10 5, 19 1, 1 1), (5 15, 7 19, 9 15, 5 15), (11 15, 13 19, 15 15, 11 15)), ((5 25, 9 25, 7 29, 5 25)), ((11 25, 15 25, 13 29, 11 25)))
Common Data Language (CDL):

netcdf sample_multipolygons_holes {
dimensions:
	node = 25 ;
	instance = 1 ;
	part = 6 ;
variables:
	double x(node) ;
		x:units = "degrees_east" ;
		x:standard_name = "longitude" ;
		x:axis = "X" ;
	double y(node) ;
		y:units = "degrees_north" ;
		y:standard_name = "latitude" ;
		y:axis = "Y" ;
	float geometry_container ;
		geometry_container:geometry_type = "polygon" ;
		geometry_container:node_count = "node_count" ;
		geometry_container:node_coordinates = "x y" ;
		geometry_container:grid_mapping = "grid_mapping" ;
		geometry_container:part_node_count = "part_node_count" ;
		geometry_container:interior_ring = "interior_ring" ;
	int node_count(instance) ;
		node_count:long_name = "count of coordinates in each instance geometry" ;
	float grid_mapping ;
		grid_mapping:grid_mapping_name = "latitude_longitude" ;
		grid_mapping:semi_major_axis = 6378137. ;
		grid_mapping:inverse_flattening = 298.257223563 ;
		grid_mapping:longitude_of_prime_meridian = 0. ;
	int part_node_count(part) ;
		part_node_count:long_name = "count of nodes in each geometry part" ;
	int interior_ring(part) ;
		interior_ring:long_name = "type of each geometry part" ;

// global attributes:
		:Conventions = "CF-1.8" ;
data:

 x = 0, 20, 20, 0, 0, 1, 10, 19, 1, 5, 7, 9, 5, 11, 13, 15, 11, 5, 9, 7, 5, 
    11, 15, 13, 11 ;

 y = 0, 0, 20, 20, 0, 1, 5, 1, 1, 15, 19, 15, 15, 15, 19, 15, 15, 25, 25, 29, 
    25, 25, 25, 29, 25 ;

 geometry_container = _ ;

 node_count = 25 ;

 grid_mapping = _ ;

 part_node_count = 5, 4, 4, 4, 4, 4 ;

 interior_ring = 0, 1, 1, 1, 0, 0 ;
}
twhiteaker commented

Yep! Now we just need to nail down what we're doing with axis and bounds.