Changes in Iris

Release 0.9 (14 Aug, 2012)

Features added

• Iris is now an open source project. See Iris on github.
• Hybrid vertical coordinates are implemented with the new AuxCoordFactory.
• More graceful loading of units. See here for more details.

Incompatible changes

• The Iris data model is now fully aligned with the CF data model . Iris remains file-format independent, as is the underlying CF data model.
• Cube merging has been re-written for the new CF data model with the benefit that some corner cases are now better handled. Some users may find that their cubes, once merged, now have a smaller total shape and more intelligent handling of dimension coordinate picking.

Deprecations

• None

---

Release 0.8 (29 May, 2012)

Features added

• Cube trajectory extraction now supports irregular grids (ORCA2) using nearest-neighbour interpolation.
• Support cube arithmetic with masked array data.
• PP loading now utilises improved field-code to standard_name/unit mapping.
• Upgraded to use centrally installed and managed version 2 of PP packing library.

Incompatible changes

• The ability to add UK Met Office branding to plots has been moved to the UK Met Office’s internal monty library.
• The ability to read colour palettes from the UKMO IDL library has been moved to the UK Met Office’s internal monty library.

Deprecations

• None

---

Release 0.7 (23 Mar, 2012)

Features added

• Cubes can now have missing data in the form of numpy masked arrays. All plotting and aggregating routines should now support masked data handling without any user code changes necessary.
• GRIB2 saving now supported for common cases. GRIB loading capabilities further extended.
• NetCDF loading of multidimensional auxiliary data implemented, providing initial support for data with an ORCA grid.
• Extended the number of PP STASH code to standard name mappings.
• PP saving of non latitude, longitude cubes added.
• Cube merging has been upgraded to support optimisation of time, forecast_period and forecast_reference_time dimensionality.
• Added new gallery entry highlighting NetCDF support for rotated pole data.
• NetCDF saving should now be CF-1.5 compliant.
• Custom made colour palettes from the UKMO IDL library can now be loaded as matplotlib colour palettes (see iris.clrtools.load_clr()).
• It is now possible to iterate over multiple cubes “in step”, ensuring that the metadata is consistent between the given cubes (see iris.iterate.izip()).
• Cell methods will now appear in the printout of a cube.
• Supporting software dependency versions have been updated. Of particular note is matplotlib which has gone from version 1.0.1 up to 1.1.0 . This may have a small impact on some plot element placements.

Incompatible changes

• The call signature for custom loader functions handled via FormatSpecification has changed. Previously the signature was loader(filename, callback) and now looks like loader(filenames, callback) where filenames is an iterable of filenames.
• Custom aggregators should now create iris.analysis.Aggregator instances rather than defining a the partial creation of an Aggregate (i.e. partial(iris.analysis.Aggregate, ...) becomes iris.analsysis.Aggregator(...).
• PP STASH code ingestion is now stricter. In particular handling of partial stash codes (i.e. those without a model or section) is no longer done, meaning that some cubes which previously had a standard name may no longer have a standard name. Further work is planned to support field code translation which should provide more robust and accurate PP interpretations.
• For parity with the CF-NetCDF community ‘phenomenon_time’ has now become ‘time’.

Deprecations

• Callback functions to iris.load and iris.load_strict should no longer return a value. Updated documentation can be found at iris.load().

---

Release 0.6 (20 Jan, 2012)

Features added

• The PP loader now supports PP fields with a header release number of 3. (As used by the UM version 8.1)
• Initial support for multidimensional coordinates (i.e. those which span multiple cube data dimensions) with the standard ExplicitCoord class.
• Added cube to CF-netCDF saving.
• Print of a cube now supports multi-dimensional coordinates, and re-categorisation of cube coordinates into “dimensioned”, “scalar” and “other” (i.e. neither dimensioned or scalar).
• Provide support for CF-netCDF label variables and 1-D auxiliary coordinate variables.

Incompatible changes

• The cube.coords dictionary has been replaced with the cube.coord and cube.coords methods for easier identification of coordinates.
• iris.cdm.coords has been moved and separated to iris.coords and iris.coord_systems.
• CF-netCDF global attributes are now put in the cube “attributes” dictionary rather than as scalar cube coordinates. Additionally any “unused” CF-netCDF variable attributes are also put in the cube “attributes” dictionary.

Deprecations

• cube.axes is now deprecated and read-only. A coordinate’s dimensions on a cube can be found with the cube.coord_dims method. An interim cube convenience property “axes” is provided to support legacy getter functionality.
• cube.axis_length is now deprecated. A cube’s shape can be determined with cube.shape and the dimensions to which a coordinate is associated can be determined with cube.coord_dims.

---

Release 0.5 (31 Oct, 2011)

• Overhaul to NetCDF loading. Iris will now load a far wider variety of CF compliant NetCDF files.
• Cubes loaded from PP will now have the associated “STASH” code in MSI format within the cube custom “attributes” dictionary.
• Cubes now have an “attributes” dictionary which can be used for phenomenon definition - cubes with different attributes are representing fundamentally different phenomenon.
• Strings can now be used to constrain standard name on load/extract.
• Plotting routines now pick the colour palettes based on the cube to plot.
• Added ability to derive area weights from a shapely geometry.
• Cubes can now be operated on (added, muliplied, etc.) using numpy arrays.
• New example of how to load custom ascii files into Cubes.
• Percentile aggregation added.
• Deferred data loading for Cubes loaded from netCDF.
• Pickle support for cubes. Pickling should be reserved for short term storage and optimisation purposes only as pickle files will not be compatible across releases.