14. Glossary

This section will define a few of the technical words used throughout this document. [Please let us know of any additions to this list which you feel would be helpful -- the authors]

typecode: a single character describing the format of the data stored in an array. For example, 'b' refers to unsigned byte-sized integers (0-255).

ufunc / universal function: a ufunc is a callable object which performs operations on all of the elements of its arguments, which can be lists, tuples, or arrays. Many ufuncs are defined in the umath module.

array / multiarray: an array refers to the Python object type defined by the NumPy extensions to store and manipulate numbers efficiently.

UserArray: The UserArray module defines a UserArray class which should be subclassed by users wishing to have classes which behave similarly to the array object type.

Matrix: The Matrix module defines a subclass Matrix of the UserArray class which is specialized for linear algebra matrices. Most notably, it overrides the multiplication operator on Matrix instances to perform matrix multiplication instead of element-wise multiplication.

rank: the rank of an array is the number of dimensions it has, or the number of integers in its shape tuple.

shape: array objects have an attribute called shape which is necessarily a tuple. An array with an empty tuple shape is treated like a scalar (it holds one element).

 

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