minor (of a matrix)
Given an matrix with entries , a minor of is
the determinant of a smaller matrix formed from its entries by selecting
only some of the rows and columns. Let and
be subsets of and
, respectively. The indices are chosen such that
and . The -th
order minor defined by and is the following determinant
If exceeds either or , then the minor is automatically zero. When , the minor is simply the determinant of the matrix. If , then the minor is called principal. The word minor may also refer to just the matrix formed from the selected rows and columns, not necessarily its determinant. The precise meaning is usually clear from context.
There does not seem to be a standard notation for matrix minors. Another possible notation is .
Some authors reserve the term minor for the case when only one
row and one column are removed. This use is in conjunction with the
concept of a cofactor
(http://planetmath.org/LaplaceExpansion).
Title | minor (of a matrix) |
---|---|
Canonical name | MinorofAMatrix |
Date of creation | 2013-03-22 14:07:01 |
Last modified on | 2013-03-22 14:07:01 |
Owner | CWoo (3771) |
Last modified by | CWoo (3771) |
Numerical id | 7 |
Author | CWoo (3771) |
Entry type | Definition |
Classification | msc 15A15 |
Related topic | LaplaceExpansion |
Related topic | CauchyBinetFormula |
Defines | principal minor |
Defines | cofactor |