APPENDIX B Version Notes

CDMS version 3.0 is a significant enhancement of previous versions. The major changes were:

CDAT/CDMS was integrated with the Numerical Python masked array class MA.MaskedVariable. The MV submodule was added as a wrapper around MA.
Methods that read data, such as subRegion, subSlice, and the slice operations, return instances of class TransientVariable. The plot and regrid modules were modified to handle masked array input. The specifiers time=..., latitude=..., etc. were added to the I/O routines.
The class TransientVariable was added.
A number of new functions were added, notably subRegion and subSlice, which return instances of TransientVariable.
When a masked array is returned from a method, it is "squeezed": singleton dimensions are removed. In contrast, transient variables are not squeezed. I/O functions have a squeeze option. The method setAutoReshapeMode was removed.
Internal attributes are handled in the InternalAttributes class. This allows CDMS classes to be subclassed more readily.
The class Variable was renamed DatasetVariable.
The cu module was emulated in cdms. cu and cdms methods can be mixed.
The code was modularized, so that Python, CDMS, and Numerical Python can be built and installed separately. This significantly enhances the portability of the code.

Functions getDomain, getSlice, rank, regrid, setMissing, size, subRegion, and subSlice were added.
The functions getRegion, getSlice, getValue, and the slice operators all return an instance of MA, a masked array. Singleton dimensions are squeezed.
The functions subRegion and subSlice return an instance of TransientVariable. Singleton dimensions are not squeezed.
The xxSlice and xxRegion functions have keywords time, level, latitude, and longitude .
The input functions have the keyword squeeze .
AbstractVariable inherits from class Slab. The following functions previously available in module cu are Slab methods: getattribute, setattribute, listdimattributes, getdimattribute, listall, and info.
AbstractVariable implements arithmetic functions, astype.
The write function was added.

The functions asComponentTime, asRelativeTime, clone, getAxisIds, getAxisIndex, getAxisList, getAxisListIndex, mapIntervalExt were added.
subaxis was renamed subAxis for consistency.
Generalized wraparound was implemented, to handle multiple cycles, reversing, and negative strides. By default, coordinate intervals are closed. The intersection options `n','e','b',and 's' were added to the interval indicator - see mapIntervalExt.

The functions asVariable, isVariable, and createVariable were added.
The function setAutoReshapeMode was removed. It is replaced by the squeeze option for all I/O functions.

The function createVariable has a keyword fill_value. The datatype may be a Numeric/MA typecode.
The function write was added.

The class InternalAttributes was added. It has methods add_internal_attribute, is_internal_attribute, and replace_external_attributes.

The class TransientVariable was added. It inherits from both AbstractVariable and MA.
The cdms module function createVariable returns a transient variable.
This class does not implement the functions getPaths or getTemplate.