nd.io package

nd.io.add_time(ds, inplace=False)[source]

Add a time dimension to the dataset.

Parameters

ds (xarray.Dataset) – The input dataset.

Returns

A dataset that is guaranteed to contain the dimension time.

Return type

xarray.Dataset

nd.io.assemble_complex(ds, inplace=False)[source]

Reassemble complex valued data.

NOTE: Changes the dataset (view) in place!

Parameters

  • ds (xarray.Dataset) – The input dataset with complex variables split into real and imaginary parts.

  • inplace (bool, optional) – Whether to modify the dataset inplace (default: False).

Returns

If inplace, returns None. Otherwise, returns a dataset where the real and imaginary parts have been combined into the respective complex variables.

Return type

xarray.Dataset or None

nd.io.disassemble_complex(ds, inplace=False)[source]

Disassemble complex valued data into real and imag parts.

Parameters

  • ds (xarray.Dataset) – The input dataset with complex variables.

  • inplace (bool, optional) – Whether to modify the dataset inplace (default: False).

Returns

If inplace, returns None. Otherwise, returns a dataset where all complex variables have been split into their real and imaginary parts.

Return type

xarray.Dataset or None

nd.io.open_beam_dimap(path, read_data=True, as_complex=True)[source]

Read a BEAM Dimap product into an xarray Dataset.

BEAM Dimap is the native file format of the SNAP software. It consists of a *.dim XML file and a *.data directory containing the data. path should point to the XML file.

Parameters

  • path (str) – The file path to the BEAM Dimap product.

  • read_data (bool, optional) – If True (default), read all data. Otherwise, read only the metadata.

Returns

The same dataset converted into xarray.

Return type

xarray.Dataset

nd.io.open_dataset(path, *args, **kwargs)[source]

The default way of reading a dataset from disk.

Determines the file format from the extension, and calls either nd.io.open_netcdf(), nd.io.open_beam_dimap(), or nd.io.open_rasterio().

Parameters

  • path (str) – The file path.

  • *args (list) – Extra positional arguments passed on to the specialized open_* function.

  • **kwargs (dict) – Extra keyword arguments passed on to the specialized open_* function.

Returns

The opened dataset. In general, if the file is a NetCDF or BEAM-Dimap file the result will be an xarray Dataset, otherwise an xarray DataArray.

Return type

xarray.Dataset or xarray.DataArray

Raises

IOError – Raises an IOError if the Dataset could not be opened.

nd.io.open_netcdf(path, as_complex=False, *args, **kwargs)[source]

Read a NetCDF file into an xarray Dataset.

Wrapper function for xarray.open_dataset that preserves complex valued data.

Parameters

  • path (str) – The path of the NetCDF file to read.

  • as_complex (bool, optional) – Whether or not to assemble real and imaginary parts into complex (default: False).

  • *args (list) – Extra positional arguments passed on to xarray.open_dataset.

  • **kwargs (dict) – Extra keyword arguments passed on to xarray.open_dataset.

Returns

The opened dataset.

Return type

xarray.Dataset

See also

  • xarray.open_dataset

nd.io.open_rasterio(path, *args, **kwargs)[source]
nd.io.to_netcdf(ds, path, *args, **kwargs)[source]

Write an xarray Dataset to disk.

In addition to xarray.to_netcdf, this function allows to store complex valued data by converting it to a a pair of reals. This process is reverted when reading the file via from_netcdf.

Parameters

  • ds (xarray.Dataset) – The dataset to be stored to disk.

  • path (str) – The path of the target NetCDF file.

  • *args (list) – Extra positional arguments for xr.Dataset.to_netcdf.

  • **kwargs (dict) – Extra keyword arguments for xr.Dataset.to_netcdf.