Submatrix (original) (raw)
A submatrix is a matrix formed by taking certain rows and columns from a bigger matrix.
For example
Then
is a submatrix of A formed by rows 1,2 and columns 1,3,4. This submatrix can also be denoted by A(3;2) which means that it is formed by deleting row 3 and column 2.
There is no standard way to denote a submatrix - although the above two methods are the most common - so one should be careful while reading an article on matrix theory.
The corresponding concept in determinant theory is of minor determinant, that is, determinant of a square submatrix.