What’s new in Iris 1.2

Release:1.2.0 Date:unreleased

This document explains the new/changed features of Iris in version 1.2.

Iris 1.2 features

A summary of the main features added with version 1.2:

• iris.cube.Cube.convert_units() and iris.coords.Coord.convert_units() have been added. This is aimed at simplifying the conversion of a cube or coordinate from one unit to another. For example, to convert a cube in kelvin to celsius, one can now call cube.convert_units(‘celsius’). The operation is in-place and if the units are not convertible an exception will be raised.
• iris.cube.Cube.var_name, iris.coords.Coord.var_name and iris.aux_factory.AuxCoordFactory.var_name attributes have been added. This attribute represents the CF variable name of the object. It is populated when loading from CF-netCDF files and is used when writing to CF-netCDF. A var_name keyword argument has also been added to the iris.cube.Cube.coord(), iris.cube.Cube.coords() and iris.cube.Cube.aux_factory() methods.
• iris.coords.Coord.is_compatible() has been added. This method is used to determine whether two coordinates are sufficiently alike to allow operations such as iris.coords.Coord.intersect() and iris.analysis.interpolate.regrid() to take place. A corresponding method for cubes, iris.cube.Cube.is_compatible(), has also been added.
• Printing a Cube is now more user friendly with regards to dates and time. All time and forecast_reference_time scalar coordinates now display human readable date/time information.
• The units of a Cube are now shown when it is printed.
• The area weights calculated by iris.analysis.cartography.area_weights() may now be normalised relative to the total grid area.
• Weights may now be passed to iris.cube.Cube.rolling_window() aggregations, thus allowing arbitrary digital filters to be applied to a Cube.

Bugs fixed

• The GRIB hindcast interpretation of negative forecast times can be enabled via the iris.fileformats.grib.hindcast_workaround flag.
• The NIMROD file loader has been extended to cope with orography vertical coordinates.

Incompatible changes

• The deprecated iris.cube.Cube.unit and iris.coords.Coord.unit attributes have been removed.

Deprecations

• The iris.coords.Coord.unit_converted() method has been deprecated. Users should make a copy of the coordinate using iris.coords.Coord.copy() and then call the iris.coords.Coord.convert_units() method of the new coordinate.
• With the addition of the var_name attribute the signatures of DimCoord and AuxCoord have changed. This should have no impact if you are providing parameters as keyword arguments, but it may cause issues if you are relying on the position/order of the arguments.
• Iteration over a Cube has been deprecated. Instead, users should use iris.cube.Cube.slices().