def __init__(self, src_grid_cube, target_grid_cube,
extrapolation_mode='linear'):
"""
Create a linear regridder for conversions between the source
and target grids.
Args:
* src_grid_cube:
The :class:`~iris.cube.Cube` providing the source grid.
* target_grid_cube:
The :class:`~iris.cube.Cube` providing the target grid.
Kwargs:
* extrapolation_mode:
Must be one of the following strings:
* 'linear' - The extrapolation points will be calculated by
extending the gradient of closest two points.
* 'nan' - The extrapolation points will be be set to NaN.
* 'error' - An exception will be raised, notifying an
attempt to extrapolate.
* 'mask' - The extrapolation points will always be masked, even
if the source data is not a MaskedArray.
* 'nanmask' - If the source data is a MaskedArray the
extrapolation points will be masked. Otherwise they will be
set to NaN.
Default mode of extrapolation is 'linear'
"""
# Snapshot the state of the cubes to ensure that the regridder
# is impervious to external changes to the original source cubes.
self._src_grid = eregrid._snapshot_grid(src_grid_cube)
self._target_grid = eregrid._snapshot_grid(target_grid_cube)
# The extrapolation mode.
if extrapolation_mode not in _LINEAR_EXTRAPOLATION_MODES:
msg = 'Extrapolation mode {!r} not supported.'
raise ValueError(msg.format(extrapolation_mode))
self._extrapolation_mode = extrapolation_mode
# The need for an actual Cube is an implementation quirk
# caused by the current usage of the experimental regrid
# function.
self._target_grid_cube_cache = None
def __init__(self, src_grid_cube, target_grid_cube, mdtol=0):
"""
Create an area-weighted regridder for conversions between the source
and target grids.
Args:
* src_grid_cube:
The :class:`~iris.cube.Cube` providing the source grid.
* target_grid_cube:
The :class:`~iris.cube.Cube` providing the target grid.
Kwargs:
* mdtol (float):
Tolerance of missing data. The value returned in each element of
the returned array will be masked if the fraction of masked data
exceeds mdtol. mdtol=0 means no missing data is tolerated while
mdtol=1 will mean the resulting element will be masked if and only
if all the contributing elements of data are masked.
Defaults to 0.
"""
# Snapshot the state of the cubes to ensure that the regridder is
# impervious to external changes to the original source cubes.
self._src_grid = eregrid._snapshot_grid(src_grid_cube)
self._target_grid = eregrid._snapshot_grid(target_grid_cube)
# Missing data tolerance.
msg = 'Value for mdtol must be in range 0 - 1, got {}.'
if mdtol < 0 or mdtol > 1:
raise ValueError(msg.format(mdtol))
self._mdtol = mdtol
# The need for an actual Cube is an implementation quirk caused by the
# current usage of the experimental regrid function.
self._target_grid_cube_cache = None