This document explains the changes made to Iris for this release (:doc:`View all changes <index>`.)
- Multiple cubes can now be exported to a NetCDF file.
- Correct nearest-neighbour calculation with circular coords.
- :ref:`Experimental regridding enhancements<exp-regrid>`.
- :ref:`Iris-Pandas interoperability<iris-pandas>`.
- NIMROD level type 12 (levels below ground) can now be loaded.
- :ref:`Load cubes from the internet via OPeNDAP<load-opendap>`.
- :ref:`GeoTiff export (experimental)<geotiff_export>`.
- :ref:`Cube merge update<cube-merge-update>`.
- :ref:`Unambiguous season year naming<season-year-name>`.
- NIMROD files with multiple fields and period of interest can now be loaded.
- Missing values are now handled when loading GRIB messages.
- PP export rule to calculate forecast period.
- :func:`~iris.cube.Cube.aggregated_by` now maintains array masking.
- IEEE 32bit fieldsfiles can now be loaded.
- NetCDF transverse mercator and climatology data can now be loaded.
- Polar stereographic GRIB data can now be loaded.
- :ref:`Cubes with no vertical coord can now be exported to GRIB<grib-novert>`.
- :ref:`Simplified resource configuration<simple_cfg>`.
- :ref:`Extended GRIB parameter translation<grib_params>`.
- Added an optimisation for single-valued coordinate constraints.
- :ref:`One dimensional linear interpolation fix<one-d-linear>`.
- :ref:`Fix for iris.analysis.calculus.differentiate<calc-diff-fix>`.
- Fixed pickling of cubes with 2D aux coords from NetCDF.
- Fixed bug which ignored the "coords" keyword for certain plots.
- Use the latest release of Cartopy, v0.8.0.
Bilinear, area-weighted and area-conservative regridding functions are now available in :mod:`iris.experimental`. These functions support masked data and handle derived coordinates such as hybrid height. The final API is still in development.
In the meantime:
:func:`~iris.experimental.regrid.regrid_bilinear_rectilinear_src_and_grid` can be used to regrid a cube onto a horizontal grid defined in a differentiate coordinate system. The data values are calculated using bilinear interpolation.
For example:
from iris.experimental.regrid import regrid_bilinear_rectilinear_src_and_grid
regridded_cube = regrid_bilinear_rectilinear_src_and_grid(source_cube, target_grid_cube):func:`~iris.experimental.regrid.regrid_area_weighted_rectilinear_src_and_grid` can be used to regrid a cube such that the data values of the resulting cube are calculated using the area-weighted mean.
For example:
from iris.experimental.regrid import regrid_area_weighted_rectilinear_src_and_grid as regrid_area_weighted
regridded_cube = regrid_area_weighted(source_cube, target_grid_cube):func:`~iris.experimental.regrid_conservative.regrid_conservative_via_esmpy` can be used for area-conservative regridding between geographical coordinate systems. This uses the ESMF library functions, via the ESMPy interface.
For example:
from iris.experimental.regrid_conservative import regrid_conservative_via_esmpy
regridded_cube = regrid_conservative_via_esmpy(source_cube, target_grid_cube)Conversion to and from Pandas Series and DataFrames is now available. See :mod:`iris.pandas` for more details.
Cubes can now be loaded directly from the internet, via OPeNDAP.
For example:
cubes = iris.load("http://geoport.whoi.edu/thredds/dodsC/bathy/gom15")With this experimental feature, two dimensional cubes can now be exported to GeoTiff files.
For example:
from iris.experimental.raster import export_geotiff
export_geotiff(cube, filename)Note
This is a raw data export only and does not save Iris plots.
Cube merging now favours numerical coordinates over string coordinates to describe a dimension, and :class:`~iris.coords.DimCoord` over :class:`~iris.coords.AuxCoord`. These modifications prevent the error: "No functional relationship between separable and inseparable candidate dimensions".
The default names of categorisation coordinates are now less ambiguous. For example, :func:`~iris.coord_categorisation.add_month_number` and :func:`~iris.coord_categorisation.add_month_fullname` now create "month_number" and "month_fullname" coordinates.
Iris can now export cubes with no vertical coord to GRIB. The solution is still under discussion: See #519.
A new configuration variable called :data:`iris.config.TEST_DATA_DIR`
has been added, replacing the previous combination of
:data:`iris.config.MASTER_DATA_REPOSITORY` and
:data:`iris.config.DATA_REPOSITORY`. This constant should be the path
to a directory containing the test data required by the unit tests. It can
be set by adding a test_data_dir entry to the Resources section of
site.cfg. See :mod:`iris.config` for more details.
- More GRIB2 params are recognised on input.
- Now translates some codes on GRIB2 output.
- Some GRIB2 params may load with a different standard_name.
:func:`~iris.analysis.interpolate.linear` can now extrapolate from a single point assuming a gradient of zero. This prevents an issue when loading cross sections with a hybrid height coordinate, on a staggered grid and only a single orography field.
A bug in :func:`~iris.analysis.calculus.differentiate` that had the potential to cause the loss of coordinate metadata when calculating the curl or the derivative of a cube has been fixed.
- As part of simplifying the mechanism for accessing test data, :func:`iris.io.select_data_path`, :data:`iris.config.DATA_REPOSITORY`, :data:`iris.config.MASTER_DATA_REPOSITORY` and :data:`iris.config.RESOURCE_DIR` have been removed.
- The add_custom_season_* functions from :mod:`~iris.coord_categorisation` have been deprecated in favour of adding their functionality to the add_season_* functions