Creator¶

The Creator class provides the interface for creating coordinates, data variables, and setting the CRS. It is accessed via ds.create on a writable dataset.

Usage¶

with cfdb.open_dataset(file_path, flag='n') as ds:
    # Create coordinates
    lat = ds.create.coord.lat(data=lat_data)
    lon = ds.create.coord.lon(data=lon_data)

    # Create data variables
    temp = ds.create.data_var.generic('temperature', ('latitude', 'longitude'), dtype='float32')

    # Set CRS
    ds.create.crs.from_user_input(4326, x_coord='longitude', y_coord='latitude')

Sub-Objects¶

Attribute	Class	Description
`ds.create.coord`	Coord	Coordinate creation
`ds.create.data_var`	DataVar	Data variable creation
`ds.create.crs`	CRS	CRS assignment

Coord¶

generic(name, data=None, dtype=None, chunk_shape=None, step=False, axis=None)¶

Create a coordinate with full control over all parameters.

coord = ds.create.coord.generic(
    'depth',
    data=np.array([0, 10, 50, 100], dtype='float32'),
    chunk_shape=(4,),
    axis='z',
)

like(name, coord, copy_data=False)¶

Create a coordinate from an existing one's parameters.

new_lat = ds.create.coord.like('new_latitude', ds['latitude'], copy_data=True)

Template Methods¶

Template methods set standard names, dtypes, and attributes automatically. They accept data, step, and any generic() kwargs.

Method	Standard Name	Default Axis
`lat`	latitude	y
`lon`	longitude	x
`time`	time	t

Additional templates are generated from cfdb-vars. To see all available templates:

with cfdb.open_dataset(file_path, flag='n') as ds:
    print(dir(ds.create.coord))

Template signature:

ds.create.coord.lat(data=None, step=True, **kwargs) -> Coordinate

DataVar¶

generic(name, coords, dtype, chunk_shape=None)¶

Create a data variable linked to existing coordinates.

temp = ds.create.data_var.generic(
    'temperature',
    ('latitude', 'longitude'),
    dtype='float32',
    chunk_shape=(20, 36),
)

like(name, data_var)¶

Create a data variable from an existing one's parameters.

new_temp = ds.create.data_var.like('temp_copy', ds['temperature'])

Template Methods¶

Data variable templates set standard names and dtypes. They accept coords and any generic() kwargs.

Method	Standard Name
Various	Generated from cfdb-vars

Template signature:

ds.create.data_var.air_temperature(coords, **kwargs) -> DataVariable

To see all available templates:

with cfdb.open_dataset(file_path, flag='n') as ds:
    print(dir(ds.create.data_var))

CRS¶

from_user_input(crs, x_coord=None, y_coord=None, xy_coord=None)¶

Set the dataset's coordinate reference system and assign spatial axes.

For grid datasets with separate x/y coordinates:

ds.create.crs.from_user_input(4326, x_coord='longitude', y_coord='latitude')

For ts_ortho datasets with a geometry coordinate:

ds.create.crs.from_user_input(4326, xy_coord='station')

The crs parameter accepts anything pyproj.CRS.from_user_input() understands: EPSG codes (int), WKT strings, PROJ strings, etc.