xcdat.regridder.accessor.RegridderAccessor

class xcdat.regridder.accessor.RegridderAccessor(dataset)

An accessor class that provides regridding attributes and methods on xarray Datasets through the .regridder attribute.

Examples

Import RegridderAccessor class:

>>> import xcdat  # or from xcdat import regridder

Use RegridderAccessor class:

>>> ds = xcdat.open_dataset("/path/to/file")
>>>
>>> ds.regridder.<attribute>
>>> ds.regridder.<method>
>>> ds.regridder.<property>

Parameters

dataset (xr.Dataset) – A Dataset object.

__init__(dataset)

Methods

__init__(dataset)
horizontal(data_var, output_grid[, tool])	Apply horizontal regridding to data_var of the current xr.Dataset to output_grid.
horizontal_regrid2(data_var, output_grid, ...)	Pure python implementation of CDAT's regrid2 horizontal regridder.
horizontal_xesmf(data_var, output_grid, ...)	Wraps the xESMF library providing access to regridding between structured rectilinear and curvilinear grids.

Attributes

grid	Returns xr.Dataset containing grid information.

_ds

property grid

Returns xr.Dataset containing grid information.

Returns

xr.Dataset – With data variables describing the grid.

Raises

ValueError – If axis data variable is not correctly identified.

_get_axis_data(name)

horizontal_xesmf(data_var, output_grid, **options)

Wraps the xESMF library providing access to regridding between structured rectilinear and curvilinear grids.

Regrids data_var in dataset to output_grid.

Option documentation xcdat.regridder.xesmf.XESMFRegridder()

Parameters

• data_var (str) – Name of the variable in the xr.Dataset to regrid.

• output_grid (xr.Dataset) – Dataset containing output grid.

• options (Dict[str, Any]) – Dictionary with extra parameters for the regridder.

Returns

xr.Dataset – With the data_var variable on the grid defined in output_grid.

Raises

ValueError – If tool is not supported.

Examples

Generate output grid:

>>> output_grid = xcdat.create_gaussian_grid(32)

Regrid data to output grid using xesmf:

>>> ds.regridder.horizontal_xesmf("ts", output_grid)

horizontal_regrid2(data_var, output_grid, **options)

Pure python implementation of CDAT’s regrid2 horizontal regridder.

Regrids data_var in dataset to output_grid using regrid2’s algorithm.

Options documentation xcdat.regridder.regrid2.Regrid2Regridder()

Parameters

• data_var (str) – Name of the variable in the xr.Dataset to regrid.

• output_grid (xr.Dataset) – Dataset containing output grid.

• options (Dict[str, Any]) – Dictionary with extra parameters for the regridder.

Returns

xr.Dataset – With the data_var variable on the grid defined in output_grid.

Raises

ValueError – If tool is not supported.

Examples

Generate output grid:

>>> output_grid = xcdat.create_gaussian_grid(32)

Regrid data to output grid using regrid2:

>>> ds.regridder.horizontal_regrid2("ts", output_grid)

horizontal(data_var, output_grid, tool='xesmf', **options)

Apply horizontal regridding to data_var of the current xr.Dataset to output_grid.

Supported tools:

• xESMF (https://pangeo-xesmf.readthedocs.io/en/latest/)

  • Rectilinear and curvilinear grids

  • Find options at xcdat.regridder.xesmf.XESMFRegridder()

• Regrid2

  • Rectilinear grids

  • Find options at xcdat.regridder.regrid2.Regrid2Regridder()

Parameters

• data_var (str) – Name of the variable in the xr.Dataset to regrid.

• output_grid (xr.Dataset) – Dataset containing output grid.

• tool (str) – Name of the regridding tool.

• **options (Dict[str, Any]) – These options are passed to the tool being used for regridding. See specific regridder documentation for available options.

Returns

xr.Dataset – With the data_var variable on the grid defined in output_grid.

Raises

ValueError – If tool is not supported.

Examples

Create destination grid:

>>> output_grid = xcdat.create_uniform_grid(-90, 90, 4.0, -180, 180, 5.0)

Regrid variable using “xesmf”:

>>> ds.regridder.horizontal("ts", output_grid, tool="xesmf", method="bilinear")

Regrid variable using “regrid2”:

>>> ds.regridder.horizontal("ts", output_grid, tool="regrid2")

Use convenience methods:

>>> ds.regridder.horizontal_xesmf("ts", output_grid, method="bilinear")

>>> ds.regridder.horizontal_regrid2("ts", output_grid)