pyresample.utils package
Submodules
pyresample.utils.cartopy module
Classes for geometry operations.
See the related Cartopy pull request that implements this functionality directly in Cartopy: https://github.com/SciTools/cartopy/pull/1888
pyresample.utils.cf module
Load an AreaDefinition object from a netCDF/CF file.
- pyresample.utils.cf.load_cf_area(nc_file, variable=None, y=None, x=None)
Load an AreaDefinition object from a netCDF/CF file.
- Parameters:
nc_file (string or object) – path to a netCDF/CF file, or opened xarray.Dataset object
variable (string, optional) – name of the variable to load the AreaDefinition from. If the variable is not a CF grid_mapping container variable, it should be a variable having a :grid_mapping attribute. If variable is None the file will be searched for valid CF area definitions
y (string, optional) – name of the variable to use as ‘y’ axis of the CF area definition If y is None an appropriate ‘y’ axis will be deduced from the CF file
x (string, optional) – name of the variable to use as ‘x’ axis of the CF area definition If x is None an appropriate ‘x’ axis will be deduced from the CF file
- Returns:
are_def, cf_info – cf_info holds info about how the AreaDefinition was defined in the CF file.
- Return type:
geometry.AreaDefinition object, dict
pyresample.utils.errors module
Special exceptions and warnings specific to pyresample.
pyresample.utils.proj4 module
Utilities for working with projection parameters.
- class pyresample.utils.proj4.DaskFriendlyTransformer(src_crs, dst_crs, **kwargs)
Bases:
objectWrapper around the pyproj Transformer class that uses dask.
If the provided arrays are not dask arrays, they are converted to numpy arrays and pyproj will be called directly (dask is not used).
- classmethod from_crs(crs_from, crs_to, **kwargs)
Create transformer object from two CRS objects.
- transform(x, y, **kwargs)
Transform coordinates.
- pyresample.utils.proj4.convert_proj_floats(proj_pairs)
Convert PROJ.4 parameters to floats if possible.
- pyresample.utils.proj4.get_geodetic_crs_with_no_datum_shift(crs: CRS) CRS
Get the geodetic CRS for the provided CRS but with no prime meridian shift.
- pyresample.utils.proj4.get_geostationary_height(geos_area_crs)
Get the height parameter from a geostationary CRS.
- pyresample.utils.proj4.ignore_pyproj_proj_warnings()
Wrap operations that we know will produce a PROJ.4 precision warning.
Only to be used internally to Pyresample when we have no other choice but to use PROJ.4 strings/dicts. For example, serialization to YAML or other human-readable formats or testing the methods that produce the PROJ.4 versions of the CRS.
- pyresample.utils.proj4.proj4_dict_to_str(proj4_dict, sort=False)
Convert a dictionary of PROJ.4 parameters to a valid PROJ.4 string.
- pyresample.utils.proj4.proj4_radius_parameters(proj4_dict)
Calculate ‘a’ and ‘b’ radius parameters.
- pyresample.utils.proj4.proj4_str_to_dict(proj4_str)
Convert PROJ.4 compatible string definition to dict.
EPSG codes should be provided as “EPSG:XXXX” where “XXXX” is the EPSG number code. It can also be provided as
"+init=EPSG:XXXX"as long as the underlying PROJ library supports it (deprecated in PROJ 6.0+).Note: Key only parameters will be assigned a value of True.
pyresample.utils.rasterio module
Utilities for working with rasterio objects.
- pyresample.utils.rasterio.get_area_def_from_raster(source, area_id=None, name=None, proj_id=None, projection=None)
Construct AreaDefinition object from raster.
- Parameters:
source (str, Dataset, DatasetReader or DatasetWriter) – A file name. Also it can be
osgeo.gdal.Dataset,rasterio.io.DatasetReaderorrasterio.io.DatasetWriterarea_id (str, optional) – ID of area
name (str, optional) – Description of area
proj_id (str, optional) – ID of projection
projection (pyproj.CRS, dict, or string, optional) – Projection parameters as a CRS object or a dictionary or string of PROJ.4 parameters.
- Returns:
area_def – AreaDefinition object
- Return type:
Module contents
Miscellaneous utility functions for pyresample.
- pyresample.utils.check_and_wrap(lons, lats)
Wrap longitude to [-180:+180[ and check latitude for validity.
- Parameters:
lons (ndarray) – Longitude degrees
lats (ndarray) – Latitude degrees
- Returns:
- Longitude degrees in the range [-180:180[ and the original
latitude array
- Return type:
lons, lats
- Raises:
ValueError – If latitude array is not between -90 and 90
- pyresample.utils.check_slice_orientation(sli)
Check that the slice is slicing the right way.
- pyresample.utils.convert_def_to_yaml(*args, **kwargs)
Convert an area definition to yaml representation.
- pyresample.utils.create_area_def(*args, **kwargs)
Create an area definition.
- pyresample.utils.fwhm2sigma(fwhm)
Calculate sigma for gauss function from FWHM (3 dB level).
- pyresample.utils.generate_nearest_neighbour_linesample_arrays(source_area_def, target_area_def, radius_of_influence, nprocs=1)
Generate linesample arrays for nearest neighbour grid resampling.
- Parameters:
- Returns:
(row_indices, col_indices)
- Return type:
tuple of numpy arrays
- pyresample.utils.generate_quick_linesample_arrays(source_area_def, target_area_def, nprocs=1)
Generate linesample arrays for quick grid resampling.
- Parameters:
- Returns:
(row_indices, col_indices)
- Return type:
tuple of numpy arrays
- pyresample.utils.get_area_def(*args, **kwargs)
Get an area definition.
- pyresample.utils.load_area(*args, **kwargs)
Load an area.
- pyresample.utils.parse_area_file(*args, **kwargs)
Parse an area file.
- pyresample.utils.recursive_dict_update(d, u)
Update dictionary recursively.
Copied from:
- pyresample.utils.wrap_longitudes(lons)
Wrap longitudes to the [-180:+180[ validity range (preserves dtype).
- Parameters:
lons (numpy array) – Longitudes in degrees
- Returns:
lons – Longitudes wrapped into [-180:+180[ validity range
- Return type:
numpy array